Research ArticleAssessment of Heavy Metals Concentration in ArsenicContaminated Groundwater of the Chaco Plain Argentina
M Cecilia Gimeacutenez1 Patricia S Blanes2 Edgar E Buchhamer1
Rosa M Osicka1 Yamila Morisio3 and Silvia S Fariacuteas3
1 Departamento Quımica Analıtica Universidad Nacional del Chaco Austral Comandante Fernandez 755Presidencia Roque Saenz Pena H3700LGO Chaco Argentina
2 Area Quımica General Departamento de Quımico Fısica Facultad de Ciencias Bioquımicas y Farmaceuticas Instituto de QuımicaRosario (IQUIR) CONICETmdashUniversidad Nacional de Rosario Suipacha 531 Rosario S2002LRK Argentina
3 Gerencia Quımica Comision Nacional de Energıa Atomica Avenida General Paz 1499 San Martın B1650KNAProvincia de Buenos Aires Argentina
Correspondence should be addressed to Patricia S Blanes blanesiquir-conicetgovar
Received 16 July 2013 Accepted 19 August 2013
Academic Editors J A Jonsson I A Katsoyiannis and S K Kurunthachalam
Copyright copy 2013 M Cecilia Gimenez et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited
The occurrence and distribution of arsenic and 23 other trace elements have been investigated in groundwater from ComandanteFernandez Department in the Central region of Chaco Province Northern Argentine The arsenic concentrations samples rangedbetween 07 to 1990 120583g Lminus1 91 (119899 = 45) exceeds the 10120583g Lminus1 World Health Organization (WHO) provisional standard limitsfor drinking water Fluorine was detected in 31 of groundwater samples Furthermore there was found a significant correlationbetween As and F (1199032 = 050) indicating an association in the prevalence of both elements In addition about 78 31 1613 and 45 of groundwater samples had respectively B Fe Al Mn and Sb exceeding Codigo Alimentario Argentino (CAA)guideline values In contrast of the previously values descript the corresponding to Cr Be Ni Pb Ag Se and Zn were found belowthe quantification limit The presence of As and trace elements in groundwater represents an important issue because it can causea public health problem
1 Introduction
Among known pollutants trace elements are widely recog-nized as being potentially toxic to living organisms Watercontamination with heavy metal (HM) are mainly deter-mined by natural (ie weathering erosion of bed rocks andore deposits) [1] and anthropogenic (ie mining industriesand agriculture) processes [2]
Soils andwater containing high levels of arsenic and othertoxic trace elements can easily contaminate plants animalsand human beings in contact with them as they either pro-duce toxic effects or accumulate in plants and thereby enteranimal and human food chains [3]
Certain elements like sodium (Na) potassium (K) cal-cium (Ca) magnesium (Mg) iron (Fe) manganese (Mn)copper (Cu) cobalt (Co) and zinc (Zn) are essentially
required by living organisms in specific concentrations butmay produce toxic effects in high concentrations [2] Themain threats to human health from HM are associatedwith exposure to lead (Pb) mercury (Hg) cadmium (Cd)and arsenic (As) which are extremely prejudicial owing totheir toxicity long persistence and bioaccumulative nature[4] Their toxic effects include headache hypertension irri-tability abdominal pain nerve damages liver and kidneyproblems sideroblastic anemia intellectual disabilities fatalcardiac arrest and carcinogenesis These metals have beenextensively studied and their effects on human health regu-larly reviewed by international bodies such as the WHO [5]
Long-term drinking of arsenic contaminated water cancause severe skin diseases including skin cancer lung blad-der and kidney cancers and perhaps other internal tumorsperipheral vascular disease hypertension and diabetes [6 7]
2 ISRN Environmental Chemistry
10ndash50 50ndash100 100ndash500
Town
Main roadByroadSurface water
CampoLargo
PresidenciaRoque
Saacuteenz Pentildea
N
gt500
lt10
Arsenic (120583gL)
Figure 1 Geographical location of the study area and distribution of arsenic concentrations
It also seems to have a negative impact on reproductive pro-cesses (infant mortality and weight of newborn babies) andcardiovascular diseases [8]
The occurrence of high concentrations of As and traceelements in drinking water has been recognized over thepast two or three decades as a great public health concern inseveral parts of the world [6 9] The Chaco-Pampean plainis the largest one in Latin America and one of the largestgeographic units in the world affected by As-contaminatedgroundwater [10] In the Chaco plain (north of the Chaco-Pampean plain) the major source of arsenic in groundwateris chemical weathering of the rocks and no anthropogenicsources of contamination have been reported [11]
Particularly it has been identified that there are elevatedAs concentrations in groundwater and reported in differentregions of Argentina such as La Pampa [1] Buenos Aires [9]Chaco [11] Cordoba [12] Santiago del Estero [13] Santa Fe[14] and Tucuman [15] Provinces Detailed information ofthe arsenic concentration in the groundwater of the Central-West region of Chaco is available in recent publications highfluorine (F) andAs contents in drinkingwaters have also beenreported [11 16] In addition a positive correlation betweenAs and F has been found (1199032 = 066)
In the study area it is necessary to carry out the researchon the presence of the trace elements in groundwater whichare present in concentrations higher than theWHO referencevalues assigned for health reasons These elements wereselected taking in view the geology of the study area andpossible leaching of As and other trace metals previouslyreported in other areas in Chaco-Pampean plain [14 1517] like vanadium strontium barium chromium uraniummolybdenum manganese and selenium The residents wholives in As-contaminated areas and consume groundwater
are not only exposed to As concentrations but also to highconcentration of multiple metals that can cause adversehealth effects
This paper presents an integrated study on the occurrenceand the distribution of arsenic and heavy metals (HM) ingroundwater in the area of Comandante Fernandez in theCentral region of Chaco Province Northern Argentine Inaddition the relations between arsenic occurrence and thesechemical components are discussed from a chemical point ofview
2 Materials and Methods
21 Location of the Study Area The study area is located inthe Department Comandante Fernandez Chaco ProvinceNorthern Argentina (Figure 1) It covers an area of 1500 km2and approximately 010 million population [11] PresidenciaRoque Saenz Pena (90000 inhabitants) located between26∘4710158402710158401015840 latitudes S and 60∘2610158402910158401015840 longitudesW is themostimportant town where we could find an economy based onagricultural and livestock exploitation
This area is located within the geologic province knownas the Chaco Pampean [11] The aquifers are hosted insuperposed sequences of aeolian and fluvial sediments of thetertiary and quaternary ages [18] As there are no superficialsources of groundwater recharge of the phreatic aquifer isproduced from rainfalls while deep aquifer recharge occursfromwest to east and northwest-southeast and it is supposedto be located in the higher parts of the sub-Andean outcrops[19 20]
The studied zone has a semiarid and subtropical con-tinental type climate characterized by sultry summers andcold winters receiving an annual precipitation of 900mmbetween November and March [21]
ISRN Environmental Chemistry 3
22 Sampling and Analysis Forty-five groundwater sampleswere collected during MayndashOctober 2010 (a dry season)in rural and suburbs areas of the Comandante FernandezDepartment (Chaco Province) (Figure 1) Each sample hasbeen collected from each tube well Latitude and longitude ofthese tube wells were determined using a Garmin eTrex Leg-end Global Positioning System (Garmin Ltd UK) Specificwell information that is the depth of the well was obtainedfrom its owner The sampling points were selected takinginto account their spatial distribution in the area in order toobtain an accurately representative hydrochemistry
For all analyses cleaning and sampling procedureinvolved deionized distilled water (DDW) produced byMilliQ water (Millipore Elix 5) and high-purity solvents Allglassware and polyethylene bottles were kept in 10 (vv)HNO
3
(Merk 65) for 24 hours rinsed out with DDIand dried in a stove All tube-wells samples were collectedafter 3min flushing filtered through 045120583m membranefilters and transferred to three different polyethylene bottlesto undertake different analysis Samples for major cationsanalysis (Ca2+Mg2+ Na+ andK+) and total Aswere acidifiedwith 006M HCl For trace metals analysis samples wereacidified to pHlt 2 by addition of ultrapure nitric acid (Fluka)No acidified fractions were collected without headspaces inthe sample bottles for measurements of anions such as ClminusSO4
2minus NO3
minus F and alkalinity All the samples were kept at4∘C until analysis
23 Groundwater Analyses The physical parameters likewater temperature (T) pH and electrical conductivity (EC)were measured in situ by using a HANNAHI991301 PortablePHECTDSTemperature Meter Na+ and K+ were deter-mined by emission flame spectrometry (JENWAY PFP7)and Ca2+ and Mg2+ concentrations were determined bycomplexometric titration using ethylenediaminetetraaceticacid (005N EDTA) Chloride nitrate and fluorine ionicactivity were measured with ion-selective electrodes usingOAKTON CE pHION Mod 510 Alkalinity was analyzedby titration method with sulfuric acid and sulfate wasmeasured by turbidimetricmethod using SpectrophotometerUV-VisibleMetrolab 1700 For a better detection limit arsenicwas analyzed by hydride generation atomic absorption spec-troscopy method (HGAAS) using hollow cathode lamps at1937 nm wavelength The instrument quantification limit forthis system was 5 120583g Lminus1 an intermediate precision of lessthanplusmn10was achieved All these analyses were performed atthe Laboratories of Quımica Analıtica Universidad Nacionaldel Chaco Austral Argentina
Total concentrations of 23 trace elements (Ag Al Ba BeB Cd Co Cr Cu Fe Mn Mo Ni P Pb S Sb Se Si Sr TiV and Zn) were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES) (PERKIN ELMER5100 DV axial solid state detector cross-flow nebulizerassociated with Scott Type chamber and AS type autosampler The equipment was linearly calibrated from 1 to100 120583g Lminus1 with custom certified standard solution (MerckICP Multielement Standard Solution XIII) 1198772 values ofcalibration curves were gt0995 and no trend was observed
in the residuals for all analyzedmetals Linearity was checkedafter every 10 samples using homemade control solutionIf the recovery was greater than plusmn10 the recalibrationwas performed for the concerned element Accuracy of theprocedure it has been tested by analyzing a certified referencematerial NIST SRM 1643 c ldquoTrace elements in waterrdquo Forthe studied elements bias ranged from 2 to 7 Precisionexpressed as intermediate precision was better than 9 forall analyzed elements
24 Statistical Analysis All statistical analysis of data includ-ing maximum and minimums means and medians wasperformed using the program STATGRAPHICS 51 (Statisti-cal Graphic Corporation Manugistics Inc Rockville USA)The software Rock Ware AqQA version 1151 was used toconstruct the Piper diagrams that depicted the groundwatertypes
3 Results and Discussion
31 Physicochemical Parameters The physicochemicalparameters determined in selecting 45 groundwater samplesare shown in Table 1 Well depth ranged between 5 and220m with average value of 23m The pH values of theassorted groundwater samples varied from 650 to 894 withaverage value of 754 indicating that the waters are generallyneutral to slightly alkalineThemeasured water temperaturesvary from 226 to 275∘C with an average of 238∘C
Major ion compositions of the analyzed groundwatersamples and themajor water types are shown in Table 1 Highnitrate concentrations (max = 200mg Lminus1) are present locallyin some wells probably due to anthropogenic influencesand a significant amount of NO
3
minus is thought to be fromevaporation However since the correlation between NO
3
minus
and Clminus is weak (1199032 = 004) evaporation is unlikely to be themost important cause of the high NO
3
minus concentrationsConsiderable spatial variation is observed for the dis-
tributions of major cations with dominance of Na+ (132to 5857mg Lminus1) K+ (210 to 110mg Lminus1) Ca2+ (140 to1100mg Lminus1) and Mg2+ (054 to 400mg Lminus1) The same vari-ation is observed for distribution of major anions with dom-inance of HCO
3
minus (median value 679mg Lminus1) Clminus (medianvalue 269mg Lminus1) and SO
4
2minus (median value 209mg Lminus1)Statistical parameters are shown in Table 2
Major ion compositions plotted on a Piper diagram(Figure 2) indicate that bicarbonate and chloride were thedominant anions followed by sulfate and that sodium wasthe prevalent cation The major water types in the samplesare presented in Table 1
ECvalues vary from069 and 249mS cmminus1with amedianvalue of 250mS cmminus1 and mean value of 527mS cmminus1This may be due to contribution of Na+ HCO
3
minus Clminus andSO4
2minus In saline groundwater chloride and sulfate are alsoimportant The most saline groundwater samples are of NandashCl type (maximum Clminus concentration 8193mg Lminus1 Tables 1and 2) although NandashSO
4
2minus types are also important (max-imum SO
4
2minus concentration 3485mg Lminus1) The most signifi-cant correlations are those of chloride versus EC and sodium
4 ISRN Environmental Chemistry
Table 1 Major ions composition of groundwater from the Comandante Fernandez Department Chaco
Sample ID Depth (m) pH EC (mS cmminus1) HCO3
minus Clminus SO4
2minus NO3
minus Na+ K+ Ca2+ Mg2+ Water typeM1 30 753 262 656 269 351 231 644 710 354 165 NandashHCO3
M44 11 707 250 723 450 901 561 223 303 132 646 CandashClM45 12 681 144 298 5674 263 424 459 286 1100 400 CandashClNd non detected All concentrations are expressed as mg Lminus1
ISRN Environmental Chemistry 5
Diagrama Piper
20
20
20
40
40
40
60
60
60
80
80
80
20
20
20
40
40
40
60
60
60
80
80
80
20
8080
20
40
6060
40
60
4040
60
80
2020
80
Mg (
)
Ca () Cl ()
Na + K ()
Na + K ()
SO4
+ Cl (
) Ca + Mg ()
HCO3
+ CO
3
SO4 ()
HCO3
+ CO
3(
)
Figure 2 Piper diagram showing the chemical compositions of groundwater samples
(1199032 = 091 1199032 = 069) and sulfate versus EC and sodium(1199032 = 062 1199032 = 061) which is related to the predominanceof sodium chloride types in groundwater with higher salinitySodium bicarbonate waters are related generally with lowsalinity samples in analyzed groundwater samples the ECshows poor correlation with HCO
3
minus (1199032 = 021)Results of chemical analysis show large variations in
chemical composition and also indicate the high salinity ofmany of the groundwater samples According to Larroza andFarina [19] the salinity of groundwater in the basin of theChaco region is due to the previous existence of a shallowsea of restricted environment which has left its salts thisgeographical feature called Paranaense Sea has originatedduring the Middle and Upper Miocene The extremelyheterogeneous values of EC from groundwater could beexplained by the local variation in sedimentary and hydro-geological characteristics [13] Moreover the evaporation inarid and semiarid zones favors the increase of salinity andalkalinity [15 22]
32 Total Arsenic and Fluoride Arsenic is classified as ahuman carcinogen (Type A) based on sufficient epidemio-logic evidence linking increased mortality from liver kidneybladder and lung cancers to drinking As-contaminatedwater[23] The provisional guideline value recommended by theWHO [5] for this carcinogenic contaminant in drinkingwater is 10 120583g Lminus1 and in Argentina this would be enforcedin 2017 [24] On the basis of this criterion only 9 (445)of groundwater source is within levels recommended forconsumption whereas about 73 (3345) of all analyzedsamples showed As values above 50 120583g Lminus1 (CAA) [25]Mean concentration of total arsenic in groundwater was213 120583g Lminus1 and maximum was 1990120583g Lminus1 (Table 2) Thehighest As concentrationwas found in groundwater collectedin sample M36 The presence of arsenic in the groundwatersamples collected from this region of Argentina is naturalthe local geology and rainfall have been shown to havemajor impact on the variations of As concentration ingroundwater
6 ISRN Environmental Chemistry
Table 2 Statistical summary of the chemistry of groundwater (major ions and trace elements 119899 = 45) from Comandante Fernandez Depart-ment Chaco Northeast Argentina
Parameter Mean Median Range 10th percentil 90th percentil Standard deviationDepth (m) 220 130 500ndash220 800 500 331pH 754 751 650ndash894 690 822 055EC (mScm) 527 250 069ndash249 099 134 628HCO
Different positive correlation were observed in ground-water between As versus HCO
3
minus and Na+ (1199032 = 075 1199032 =045) and a negative correlation was found between As andCa2+ (1199032 = minus005) It could be assumed that As is associatedwith NandashHCO
3
minus system related to feldspar dissolution [26]Based on values of pH found in groundwater of this region ofChaco including data reported from other sites of the region[1 13 27] it can be presumed that pH controls As mobility
The study made by Smedley et al [28] reveals that highlyAs(V)-contaminated groundwater in oxidizing environmentsthroughout the world are characterized by high concen-tration of HCO
3
minus (gt500mg Lminus1) and SO4
2minus (gt250mg Lminus1)and pH gt 750 Similar geochemical conditions occur in theChaco-Pampean plain like in the arid regions of Santiagodel Estero Cordoba y La Pampa [13 14 27] High As con-centrations are common and dominated by As(V) and thegroundwater have correspondingly high F concentrationsThese general characteristic are consistent with the analyzed
groundwater However arsenic speciation is not performedin the present study
On the other hand smaller quantities of fluoride ion inthe order of 1mg Lminus1 in ingested water are usually consideredto have a beneficial effect by lowering the rate of occurrenceof dental caries Excessive intake (gt15mg Lminus1) would resultsin pathological changes in teeth and bones such as mottlingof teeth or dental fluorosis along with metabolic changesreported on soft tissues such as thyroid reproductive organsbrain liver and kidneys [29]
TheWHOguideline value for F concentration in drinkingwater is 15mg Lminus1 [5] whereas the Codigo AlimentarioArgentino (CCA) [25] establishes a limit that varies accordingto the average temperature of the place (1mg Lminus1 for an aver-age temperature of 215∘C in the area under study) Thedistribution of F concentrations is heterogeneous and similarto As A positive correlation was observed between As andF with 1199032 = 050 The analyzed groundwater 31 (1445) of
ISRN Environmental Chemistry 7
the samples exceeded theWHO guideline value of 15mg Lminus1[5] About 47 of all analyzed samples showed F values above1mg Lminus1 recommended by CAA (Table 4) Similar correla-tions between As and F were also observed in groundwaterfrom neighboring Santiago del Estero [13] Santa Fe [14] andSalta Provinces [30]
In the same way as arsenic the F rich water is character-ized by high concentration of Na+ and low concentration ofCa2+ and Mg2+ (1199032 = 045 009 and 016 resp) Fluoride is ahighly reactive element that combines with other elements incovalent and ionic bonds It is mainly found in alkaline rocksand alkaline soils fluorite being the principal componentGomez et al [27] explain that the processes that could controlthe low relationship between F and Ca2+ and the positiverelationship between F and bicarbonate (1199032 = 024) would bethe balance equation relating calcite and fluorite when bothare in contact with water
As and other trace elements such as V Mo U and minorelements such as B and F are presumed to have their originalsource in volcanic ashes originated from the volcanismin the Andes (5ndash25 in the loess-type sediments of theChaco-Pampean plain) [9] The main components of thesesediments are feldspars quartz volcanic glass shards andminor amounts of muscovite and calcite The compositionof volcanic glass is typically rhyolitic containing a highconcentration of F As V and B among other trace elements[28]
33 Other Trace Elements A series of various trace elementsincluding Ag Al B Ba Be Cd Co Cr Cu Fe Mn MoNi P Pb S Sb Se Si Sr Ti V and Zn were also deter-mined in the studied groundwater The concentrations oftarget elements are summarized in Table 3 Among all 23target analytes concentrations exceeding the WHO recom-mended drinking water limits (in parentheses) were foundfor B (2400120583g Lminus1) Ba (700 120583g Lminus1) Cd (3 120583g Lminus1) and Sb(20120583g Lminus1) Table 4 shows the percentage of groundwatersamples exceeding these WHO and CAA elemental concen-tration guidelines On the other hand concentrations of SnCo Cu Ni S Se Sr V and Zn were very low Silver beryl-lium chrome selenium lead and titanium are not includ inTables 2 and 3 because these elements were never found aboverespective quantification limits
From the samples investigated only one (M45) showedelevated value of barium (1400 120583g Lminus1) than in the WHOdrinking water guideline (700 120583g Lminus1) with an average valueof 122120583g Lminus1 (Table 2)
In small quantities B is essential for healthy bones jointfunction and the metabolism of steroidal hormonesBoron deficiency seems to affect calcium and magnesiummetabolism and affects the composition structure andstrength of bone [31]The concentrations of boron (B) rangedfrom 1560 to 21910 120583g Lminus1 with an average of 4020120583g Lminus1(Table 2) Boron concentration in the 44 (2045) ofthe samples exceeds the WHO and 78 (3545) of thesamples exceeds the CAA standard limits for drinking water(Table 4) The highest concentration of boron was observedin sample M40 which is associated with the largest value
of EC (19371 120583S cmminus1) In general the presence of boron ingroundwater depends on its salinity (represented as EC) suchthat it increases with increasing salinity [32] In this studya positive correlation between EC and boron (1199032 = 064)suggests that boron might be associated with the salinity ofthese samplesHence the salinitymainly reflects the variationof Clminus concentration with a strong linear correlation(1199032 = 091) between EC and Clminus suggesting that the increaseof Clminus concentration contributes to increase in EC valueThehydraulic conductivity salinity type of clay sediments pHand temperature are the crucial factors that determine boronmobility in the groundwater system [32] Boron was stronglycorrelated with Na+ K+ Mg2+ Clminus SO
4
2minus HCO3
minus andAs probably due to their common origin The correlationbetween B and As is often observed in groundwater [1 13]
Our results indicate that approximately 31 of thegroundwater samples tested exceeded the CAA criteria of300 120583g Lminus1 for total Fe in drinking water The highest totalFe concentration (2000120583g Lminus1) appeared in sample M38 Ingeneral Fe concentrationwas low in the studied groundwatersamples only fourteen samples had higher Fe with a meanvalue of 276120583g Lminus1 and median value of 81 120583g Lminus1 On theother hand weaker correlation is observed between Fe andAsin groundwater (1199032 = 017) Moreover almost all groundwa-ter with high Fe concentration (gt300120583g Lminus1) contained totalAs concentration over 10 120583g Lminus1 (Table 3)
The concentration of dissolved Al varied between 600to 17380 120583g Lminus1 with a mean value of 561120583g Lminus1 (Table 2)A 16 (745) exceeded the 200120583g Lminus1 CAA drinking waterguideline However the mean concentration of Al decreasessignificantly down to 178120583g Lminus1 (median 985120583g Lminus1) if theanomalous of sample M24 is excluded Also Aluminumshows no correlation with As (1199032 = minus006)
Manganese exceeded the 100 120583g Lminus1 CAA drinking waterguideline value in 13 (645) of the samples (Tables 3 and4) The highest Mn concentration (3740 120583g Lminus1) was foundin sample M32 However the mean concentration of Mndecreases significantly from 152 to 700 120583g Lminus1 (median500120583g Lminus1) if the anomalous value of this sample is exclud-ed Manganese shows no correlation with As (1199032 = minus007)Mn is known as an essential element for human survivalserves as a catalyst and cofactor in many enzymatic processesinvolved in the synthesis of fatty acids and cholesterol Thechronic ingestion of Mn in drinking water is associated withneurologic damage [33] Moreover manganese is a knownmutagen [34]
Many samples have Fe Al and Mn concentrationsbelow detection limits and most have below CAA guidelinevalue However concentrations are higher in a few samples(Table 2) Smedley et al [1] suggest that at the pH of thegroundwater the high concentrations for these elements traceare most likely due to presence of colloidal particles As thegroundwater are oxidizing solubility of Fe Al andMnoxidesis low and concentrations of dissolved Fe Al and Mn aretherefore mostly low
The processes of dissolution and release from oxides andoxyhydroxides mainly Al Mn and Fe control the presence
8 ISRN Environmental Chemistry
Table3Tracee
lementcom
positionof
grou
ndwater
samples
from
theC
omandanteF
ernand
ezDepartm
entCh
aco
SampleID
As(to
t)F
Al
FeMn
BBa
Mo
SiV
Cd
SrCo
Ni
ZnCu
SP (
tot)
SbQL
500
010
100
100
500
200
100
100
500
100
300
250
100
100
100
100
0025
010
250
M1
500
190
110
600
500
1598
bql
126
bql
830
500
730
bql
bql
bql
bql
110
080
bql
M2
250
050
120
401
bql
310
156
bql
309
450
bql
420
bql
bql
bql
bql
200
030
bql
M3
100
180
900
160
300
875
bql
bql
bql
100
bql
691
bql
bql
300
bql
107
290
bql
M4
150
030
100
bql
bql
206
bql
bql
bql
220
bql
290
bql
bql
bql
bql
700
030
bql
M5
127
074
220
bql
900
811
791
420
227
119bq
l594
bql
bql
410
bql
020
090
bql
M6
580
080
110
bql
bql
297
100
bql
bql
440
bql
498
bql
bql
bql
bql
700
050
bql
M7
240
040
100
bql
bql
275
482
120
bql
430
bql
230
bql
bql
bql
bql
800
030
bql
M8
120
100
100
bql
600
2654
790
bql
2099
900
300
2012
bql
bql
bql
bql
110
080
bql
M9
178
198
130
550
700
1550
101
990
549
163
700
811
bql
bql
bql
630
700
080
900
M10
500
260
800
220
870
15070
bql
160
16570
390
400
4871
bql
bql
bql
bql
725
190
bql
M11
250
224
100
bql
600
1387
bql
140
480
230
bql
641
bql
bql
bql
bql
132
050
bql
M12
110
044
100
bql
194
500
620
bql
114530
bql
334
bql
100
bql
bql
130
060
bql
M13
952
110
110
bql
500
500
269
420
bql
760
400
683
bql
bql
bql
bql
100
030
300
M14
11615
0110
bql
500
665
bql
431
bql
650
500
540
bql
bql
bql
bql
700
070
bql
M15
310
050
102
500
500
2449
402
303
680
570
bql
521
bql
bql
bql
bql
490
060
bql
M16
290
040
130
150
500
255
518
bql
490
110
bql
362
bql
bql
bql
bql
260
030
bql
M17
830
120
100
bql
bql
1782
403
bql
3940
940
300
1427
bql
bql
bql
bql
113
020
300
M18
620
080
700
bql
182
734
bql
bql
2550
280
bql
2510
bql
bql
bql
bql
281
060
bql
M19
100
020
110
bql
500
298
144
bql
bql
300
bql
157
bql
bql
bql
bql
800
050
bql
M20
112
145
100
bql
bql
2316
220
109
4750
112
300
1390
bql
bql
bql
bdl
147
040
bql
M21
700
190
100
bql
254
2470
bql
112
353
280
bql
1361
bql
bql
bql
bql
415
890
bql
M22
100
020
100
bql
292
156
169
bql
bql
bql
bql
860
bql
bql
bql
bql
600
150
bql
M23
360
030
110
bql
bql
630
109
bql
bql
300
bql
225
bql
bql
bql
bql
500
070
900
M24
860
075
17380
310
296
21560
111
bql
1380
120
300
324
bql
bql
321
bql
010
080
bql
M25
770
120
2980
bql
521
6308
bql
bql
1647
220
Bql
bql
bql
100
2831
320
010
250
400
M26
100
340
600
110
bql
1800
150
210
150
198
300
150
bql
bql
bql
bql
006
180
bql
M27
214
420
600
855
bql
6890
bql
213
150
560
300
213
280
bql
670
280
006
110
bql
M28
100
340
600
428
bql
8450
bql
214
150
219
300
150
220
bql
bql
220
006
670
bql
M29
100
060
600
660
bql
6850
bql
208
150
100
300
150
bql
bql
670
bql
006
770
bql
M30
244
090
600
810
330
3050
185
210
150
547
300
150
bql
bql
240
bql
006
130
250
M31
770
340
280
1013
230
7290
bql
210
150
2646
300
322
bql
bql
bql
bql
030
030
bql
M32
700
010
210
286
3740
5080
632
209
150
bql
300
164
640
bql
110
640
020
230
300
M33
174
170
600
734
321
2790
690
210
7540
266
300
150
bql
bql
270
bql
Bql
220
bql
M34
317
030
360
575
240
1970
118
214
150
436
300
150
bql
bql
bql
bql
040
060
bql
M35
1073
030
600
194
bql
6340
301
205
150
1249
300
150
120
bql
490
120
006
030
300
M36
1990
425
600
510
135580
bql
210
150
251
300
288
240
bql
130
bql
006
530
300
M37
200
030
570
606
131290
113
210
150
387
300
203
240
100
160
670
060
050
bql
M38
150
190
600
2000
bql
3710
bql
210
150
380
300
200
950
bql
bql
bql
006
030
300
M39
200
050
600
300
bql
4830
140
210
150
104
300
200
bql
bql
bql
670
006
990
140
ISRN Environmental Chemistry 9
Table3Con
tinued
SampleID
As(to
t)F
Al
FeMn
BBa
Mo
SiV
Cd
SrCo
Ni
ZnCu
SP (
tot)
SbM40
200
050
600
689
bql
21910
bql
210
150
124
300
200
bql
bql
bql
240
006
130
300
M41
150
150
600
988
bql
21580
bql
210
150
176
300
302
bql
bql
bql
bql
006
110
300
M42
130
080
600
426
bql
1970
bql
210
150
345
300
369
180
bql
270
111
006
020
300
M43
150
140
600
700
431
1030
107
210
150
bql
300
bql
550
bql
220
270
006
080
bql
M44
100
120
600
800
bql
2600
289
210
150
191
300
bql
bql
bql
bql
bql
006
480
bql
M45
200
160
600
262
331
240
1400
210
150
350
300
bql
bql
bql
110490
006
230
bql
QLqu
antifi
ctionlim
itbq
lbello
wqu
antifi
catio
nlim
itallcon
centratio
nsaree
xpressed
as120583gLminus1excepted
forF
Sand
Pexpressedas
mgLminus1
10 ISRN Environmental Chemistry
Table 4 Risk-based drinking water criteria and the percentage ofgroundwater samples exceeding these criteria
NA not applicablelowastWHO World Health Organization have not established risk-based drink-ing water criteria for Al Ag Be Bi Co Fe Mn Mo Si Sr Ti V and ZnlowastlowastCAA Codigo Alimentario ArgentinolowastlowastlowastProvisional guideline value
and mobility of As and F in groundwater [1] Kim et al [35]suggested that the cocontamination of As and F observed inoxidizing aquifers in many countries is associated with thedesorption from the Fe-(hydr) oxides by the pH increasesThe correlations between As and F are generally very high inthose aquifers because the As released from Fe-(hydr) oxidesdoes not readily precipitate again in the oxidizing alkalinecondition This is consistent with our observations as manyof the samples show high pH values and moderate coefficientcorrelation value between As and F (1199032 = 050) Alsosolubility of Al minerals may be enhanced by the complex ofdissolved Al with F that is also released from volcanic glasses
Vanadium in groundwater ranged between lt100 (QL)and 2646 120583g Lminus1 The highest V concentration was found insample M31 (Table 2) Vanadium shows a moderated positivecorrelation with As (1199032 = 042) and is likely to be derivedfrom similar mineral sources (secondary Fe and Mn oxides)under the high pH conditions [1] Our results also indicatethat Mo in general appears in low concentrations (Table 3)Molybdenum is weakly correlated with As (1199032 = 020)
Gomez et al [27] suggest that V U B and Mo areenriched in volcanic materials and are mobilized as vanadatemolybdate borate and so forth under oxidizing conditionsAlternatively they are mobilized in alkaline solutions under
conditions of high pH and high HCO3
minus controlled bycarbonate reactions (eg the F may be forming anioniccomplexes with B Fe and Al)
Antimony (Sb) is ubiquity a GroupV of the periodic tableand is similar to As in aspects as chemical behavior andtoxicity to animals [5] The Sb concentrations in studiedsamples exceeded 20120583g Lminus1 WHO and CAA drinking waterguideline values in 45 (245) of the analyzed samples(Tables 3 and 4)
Cadmium reaches a maximum of 70120583g Lminus1 with mostsamples being less than 30 120583g Lminus1 As this element formscationic species in solution its mobilization is not favoredunder the alkaline conditions of the groundwater [1]
The presence of arsenic and heavy metals in the samplescollected from this region of Chaco in Argentina may be dueto local geochemical conditions that facilitate the transfer ofnaturally occurring arsenic from soil and sediment to thewaterThe people in the Comandante FernandezDepartmentmay be overexposed not only toAs but also to B CdMn andF Adverse health effects may appear in coming years Thisproblem is a serious concern for the local population
4 Conclusions
The results of the current study indicate that approximately91 of the groundwater samples used for consumptionby human and livestock from the Comandante FernandezDepartment (Chaco province Argentina) exceed the WHOprovisional guideline value of 10 120583g Lminus1 As recommended asa maximum allowable level in potable water
Evaporation potentiated in arid and semiarid zonefavors the increase of salinity and alkalinity the results is alow quality of the resource but is not conditioning the con-centration of As and F Hence factors other than evaporationsuch as desorption from metal oxides and possibly silicatereaction could be likely controlling As and F mobiliza-tion Furthermore arsenic associated trace elements may beabsorbed on the surface of iron and aluminum oxides andoxyhydroxides (hematite goethite Fe(OH)
3
and gibbsite)limiting the mobility of trace elements Groundwater withhigh pH values and high concentration of bicarbonate wouldfacilitate the dissolution of volcanic glass thus trace elementsmay enter groundwater cycles forming anionic complexes inalkaline solutions and acquiring great mobility
The hydrochemical trace in the region is characterizedby high salinity and high As and F concentrations whichis related to volcanism and hydrothermal activity from theAndes This association is often linked to presence of BCd Mo Mn and V indicating their common origin in thevolcanic glasses
Due to high As concentrations found in groundwaterserious health risk must be considered The population inthe area may be exposed to the chronic toxicological effectsof hydro arsenicism and fluorosis increasing the risks ofcontracting other diseases derived from them Since thegroundwater studied here constitutes the principal source ofdrinking water in the zone mitigation efforts should not belimited to As health risks from other toxic elements presentin drinking water must also be addressed in this region
ISRN Environmental Chemistry 11
Conflict of Interest
The authors declare that there is no conflict of interestsregarding the publication of this paper Its publication isapproved by all authors and tacitly or explicitly by the respon-sible authorities where the work was carried out and that ifaccepted it will not be published elsewhere in the same formin English or in any other language including electronicallywithout the written consent of the copyright-holder
Acknowledgments
This work was supported with funds from PI 3600005 Uni-versidad Nacional del Chaco Austral (UNCAus) Patricia SBlanes thanks the National Academy of Exact Physic andNatural Sciences for granting a PhD fellowship
References
[1] P L Smedley H B Nicolli DM JMacdonald A J Barros andJ O Tullio ldquoHydrogeochemistry of arsenic and other inorganicconstituents in groundwaters from La Pampa ArgentinardquoApplied Geochemistry vol 17 no 3 pp 259ndash284 2002
[2] S Muhammad M T Shah and S Khan ldquoHealth risk assess-ment of heavy metals and their source apportionment in drink-ingwater of Kohistan region northern PakistanrdquoMicrochemicalJournal vol 98 no 2 pp 334ndash343 2011
[3] S S Farıas V A Casa C Vazquez L Ferpozzi G N Pucci andI M Cohen ldquoNatural contamination with arsenic and othertrace elements in ground waters of Argentine Pampean PlainrdquoScience of the Total Environment vol 309 no 1ndash3 pp 187ndash1992003
[4] L Jarup ldquoHazards of heavy metal contaminationrdquo British Med-ical Bulletin vol 68 pp 167ndash182 2003
[5] World Health Organization (WHO) ldquoRecommendationsrdquo inGuidelines for Drinking Water Quality vol 1 Geneva Switzer-land 4th edition 2011
[6] C Hopenhayn ldquoArsenic in drinking water impact on humanhealthrdquo Elements vol 2 no 2 pp 103ndash107 2006
[7] S H Lamm and M B Kruse ldquoArsenic ingestion and bladdercancermortalitymdashwhat do the dose-response relationships sug-gest aboutmechanismrdquoHumanandEcological RiskAssessmentvol 11 no 2 pp 433ndash450 2005
[8] C-HWang C K Hsiao C-L Chen et al ldquoA review of the epi-demiologic literature on the role of environmental arsenicexposure and cardiovascular diseasesrdquo Toxicology and AppliedPharmacology vol 222 no 3 pp 315ndash326 2007
[9] J Bundschuh M I Litter F Parvez et al ldquoOne century ofarsenic exposure in Latin America a review of history andoccurrence from 14 countriesrdquo Science of the Total Environmentvol 429 pp 2ndash35 2012
[10] M T Alarcon-Herrera J Bundschuh B Nath et al ldquoCo-occurrence of arsenic and fluoride in groundwater of semi-aridregions in Latin America genesis mobility and remediationrdquoJournal of Hazardous Materials 2012
[11] E E Buchhamer P S Blanes RM Osicka andM C GimenezldquoEnvironmental risk assessment of arsenic and fluoride in thechaco province argentina research advancesrdquo Journal of Toxi-cology and Environmental Health A vol 75 no 22-23 pp 1437ndash1450 2012
[12] A Cabrera M Blarasin E Matteoda G Villalva and M LGomez ldquoComposicion quımica del agua subterranea en el surde Cordoba lınea de base hidroquımica o fondo natural enreferencia a arsenico y fluorrdquo in Aguas Superficiales y Sub-terraneas en el sur ae Cordoba Una Perspectiva GeoambientalM Blarasin S Degiovanni A Cabera and M Villegas Edspp 81ndash90 Universidad Nacional de Rıo Cuarto Rıo CuartoArgentina 2005
[13] P Bhattacharya M Claesson J Bundschuh et al ldquoDistributionand mobility of arsenic in the Rıo Dulce alluvial aquifers inSantiago del Estero Province Argentinardquo Science of the TotalEnvironment vol 358 no 1ndash3 pp 97ndash120 2006
[14] B Nicolli O C Tujchneider M C Paris M Blanco and A JBarros ldquoMovilidad del arsenico y oligoelementos asociados enaguas subterraneas del centro-norte de la provincia de Santa FeArgentinardquo in Proceedings of the Presencia de Fluor y Arsenicoen Aguas Subterraneas VI Congreso Hidrogeologico ArgentinoG Galindo J L Fernandez Turiel and A Storniolo Eds pp81ndash90 Santa Rosa La Pampa Argentina 2009
[15] H B Nicolli A Tineo J W Garcıa C M Falcon and PL Smedley ldquoMobilization of arsenic and other trace elementof health concern in groundwater from the Salı River BasinTucuman Province Argentinardquo Environmental Geochemistryand Health vol 34 no 2 pp 251ndash262 2012
[16] RMOsicka N Agullo C Herrera Ahuad andMC GimenezldquoEvaluacion de las concentraciones de fluoruro y arsenico enlas aguas subterraneas del Domo Central de la provincia delChacordquo Comunicaciones Cientıficas y Tecnologicas Univer-sidad Nacional del Nordeste 2002 httpwwwunneeduarunneviejaWebcytcyt200208-ExactasE-049pdf
[17] C E Fiorentino J D Paoloni M E Sequeira and P ArosteguyldquoThe presence of vanadium in groundwater of southeasternextreme the pampean region Argentina Relationship withother chemical elementsrdquo Journal of Contaminant Hydrologyvol 93 no 1ndash4 pp 122ndash129 2007
[18] P Sprechmann F G Acenaloza C Gaucher A C R Nogueiraand M J Perez ldquoTrasgresion Paranaense paleoestuario deltethys del miocenomedio yo superior en Sudamericardquo in Con-greso Latinoamericano de Geologıa Montevideo-UruguayAbstracts 1 CDRoom pp 10ndash15 Sociedad Latinoamericana deGeologıa 2001
[19] F Larroza and L S Farina ldquoCaracterizacion hidrogeologica delsistema acuıfero Yrenda (SAY) en Paraguay recurso compar-tido con y Boliviardquo in Proceedings of the IV Congreso Argentinode Hidrogeologıa TOMO II Argentinarıo Cuarto CordobaArgentina 2005
[20] E Popolizio P Y Serra and G O Hort ldquoLa clasificaciontaxonomica del Chacordquo Centro de Geociencia Aplicada vol 3no 1 pp 11ndash32 1980
[21] INTA ldquoInstituto Nacional de Tecnologıa AgropecuariardquoAgrometeorologıa httpwwwintagovarsaenzpemeteorolo-giameteorologiahtm
[22] M G Garcıa O Sracek D S Fernandez andM D V HidalgoldquoFactors affecting arsenic concentration in groundwaters fromNorthwestern Chaco-Pampean Plain Argentinardquo Environmen-tal Geology vol 52 no 7 pp 1261ndash1275 2007
[23] US Environmental Protection Agency ( EPA) ldquoArsenic Inor-ganic United States Environmental Protection Agency Inte-grated Risk Information System (IRIS) (CASRN 7440-38-2)rdquo1998 httpwwwepagovirissubst0278htm
12 ISRN Environmental Chemistry
[24] Comision Nacional de Alimentos (CONAL) Acta Nž 93Reunion Ordinaria 3011 y 0112-2011 (Prorroga Art 982 y 983del CAA)
[25] CAA (Codigo Alimentario Argentino) Cap XII Bebidashıdricas agua y agua gasificada In Codigo Alimentario Argen-tino modificatoria del Art 982 (Res 682007 y 1962007) Ley18 284 Buenos Aires Argentina 2007 httpwwwanmatgovarCODIGOACapitulo XII Agua 2007-05pdf
[26] J L Fernandez Turiel G GalindoM A Parada D GimenoMGarcıa-Valles and J Saavedra ldquoEstado actual del conocimientosobre el arsenico en el agua de Argentina y Chile origenmovilidad y transporterdquo inArsenico en Agua Origen movilidady tratamiento II Seminario Hispano-Latinoamericano sobreTemas Actuales de Hidrologıa Subterranea y IV Congreso Hidro-geologico Argentino pp 1ndash22 Rıo Cuarto Argentina 2005
[27] M L Gomez M T Blarasin and D E Martınez ldquoArsenic andfluoride in a loess aquifer in the central area of Argentinardquo Envi-ronmental Geology vol 57 no 1 pp 143ndash155 2009
[28] P L Smedley D G Kinniburgh D M J Macdonald et alldquoArsenic associations in sediments from the loess aquifer of LaPampa Argentinardquo Applied Geochemistry vol 20 no 5 pp989ndash1016 2005
[29] D L Ozsvath ldquoFluoride and environmental health a reviewrdquoReviews in Environmental Science and Biotechnology vol 8 no1 pp 59ndash79 2009
[30] E M Farfan Torres P M Naranjo A Boemo I Lomnicziand L Lorenzo ldquoDistribution of arsenic in groundwater in theChaco Salteno Argentinardquo in Workshop on as Distribution inIbero-America M I Litter Ed CyTED IBEROARSENAbstractBook pp 57ndash60 2006
[31] httpwwwjctoniccomincludemineralsboronhtm[32] M A Halim R K Majumder S A Nessa et al ldquoEvaluation
of processes controlling the geochemical constituents in deepgroundwater in Bangladesh spatial variability on arsenic andboron enrichmentrdquo Journal of HazardousMaterials vol 180 no1ndash3 pp 50ndash62 2010
[33] J BuschmannM Berg C Stengel andM L Sampson ldquoArsenicand manganese contamination of drinking water resources inCambodia coincidence of risk areaswith low relief topographyrdquoEnvironmental Science and Technology vol 41 no 7 pp 2146ndash2152 2007
[34] R A Beckman A S Mildvan and L A Loeb ldquoOn the fidelityof DNA replication manganese mutagenesis in vitrordquo Biochem-istry vol 24 no 21 pp 5810ndash5817 1985
[35] S-H Kim K Kim K-S Ko Y Kim and K-S Lee ldquoCo-con-tamination of arsenic andfluoride in the groundwater of uncon-solidated aquifers under reducing environmentsrdquoChemospherevol 87 no 8 pp 851ndash856 2012
Figure 1 Geographical location of the study area and distribution of arsenic concentrations
It also seems to have a negative impact on reproductive pro-cesses (infant mortality and weight of newborn babies) andcardiovascular diseases [8]
The occurrence of high concentrations of As and traceelements in drinking water has been recognized over thepast two or three decades as a great public health concern inseveral parts of the world [6 9] The Chaco-Pampean plainis the largest one in Latin America and one of the largestgeographic units in the world affected by As-contaminatedgroundwater [10] In the Chaco plain (north of the Chaco-Pampean plain) the major source of arsenic in groundwateris chemical weathering of the rocks and no anthropogenicsources of contamination have been reported [11]
Particularly it has been identified that there are elevatedAs concentrations in groundwater and reported in differentregions of Argentina such as La Pampa [1] Buenos Aires [9]Chaco [11] Cordoba [12] Santiago del Estero [13] Santa Fe[14] and Tucuman [15] Provinces Detailed information ofthe arsenic concentration in the groundwater of the Central-West region of Chaco is available in recent publications highfluorine (F) andAs contents in drinkingwaters have also beenreported [11 16] In addition a positive correlation betweenAs and F has been found (1199032 = 066)
In the study area it is necessary to carry out the researchon the presence of the trace elements in groundwater whichare present in concentrations higher than theWHO referencevalues assigned for health reasons These elements wereselected taking in view the geology of the study area andpossible leaching of As and other trace metals previouslyreported in other areas in Chaco-Pampean plain [14 1517] like vanadium strontium barium chromium uraniummolybdenum manganese and selenium The residents wholives in As-contaminated areas and consume groundwater
are not only exposed to As concentrations but also to highconcentration of multiple metals that can cause adversehealth effects
This paper presents an integrated study on the occurrenceand the distribution of arsenic and heavy metals (HM) ingroundwater in the area of Comandante Fernandez in theCentral region of Chaco Province Northern Argentine Inaddition the relations between arsenic occurrence and thesechemical components are discussed from a chemical point ofview
2 Materials and Methods
21 Location of the Study Area The study area is located inthe Department Comandante Fernandez Chaco ProvinceNorthern Argentina (Figure 1) It covers an area of 1500 km2and approximately 010 million population [11] PresidenciaRoque Saenz Pena (90000 inhabitants) located between26∘4710158402710158401015840 latitudes S and 60∘2610158402910158401015840 longitudesW is themostimportant town where we could find an economy based onagricultural and livestock exploitation
This area is located within the geologic province knownas the Chaco Pampean [11] The aquifers are hosted insuperposed sequences of aeolian and fluvial sediments of thetertiary and quaternary ages [18] As there are no superficialsources of groundwater recharge of the phreatic aquifer isproduced from rainfalls while deep aquifer recharge occursfromwest to east and northwest-southeast and it is supposedto be located in the higher parts of the sub-Andean outcrops[19 20]
The studied zone has a semiarid and subtropical con-tinental type climate characterized by sultry summers andcold winters receiving an annual precipitation of 900mmbetween November and March [21]
ISRN Environmental Chemistry 3
22 Sampling and Analysis Forty-five groundwater sampleswere collected during MayndashOctober 2010 (a dry season)in rural and suburbs areas of the Comandante FernandezDepartment (Chaco Province) (Figure 1) Each sample hasbeen collected from each tube well Latitude and longitude ofthese tube wells were determined using a Garmin eTrex Leg-end Global Positioning System (Garmin Ltd UK) Specificwell information that is the depth of the well was obtainedfrom its owner The sampling points were selected takinginto account their spatial distribution in the area in order toobtain an accurately representative hydrochemistry
For all analyses cleaning and sampling procedureinvolved deionized distilled water (DDW) produced byMilliQ water (Millipore Elix 5) and high-purity solvents Allglassware and polyethylene bottles were kept in 10 (vv)HNO
3
(Merk 65) for 24 hours rinsed out with DDIand dried in a stove All tube-wells samples were collectedafter 3min flushing filtered through 045120583m membranefilters and transferred to three different polyethylene bottlesto undertake different analysis Samples for major cationsanalysis (Ca2+Mg2+ Na+ andK+) and total Aswere acidifiedwith 006M HCl For trace metals analysis samples wereacidified to pHlt 2 by addition of ultrapure nitric acid (Fluka)No acidified fractions were collected without headspaces inthe sample bottles for measurements of anions such as ClminusSO4
2minus NO3
minus F and alkalinity All the samples were kept at4∘C until analysis
23 Groundwater Analyses The physical parameters likewater temperature (T) pH and electrical conductivity (EC)were measured in situ by using a HANNAHI991301 PortablePHECTDSTemperature Meter Na+ and K+ were deter-mined by emission flame spectrometry (JENWAY PFP7)and Ca2+ and Mg2+ concentrations were determined bycomplexometric titration using ethylenediaminetetraaceticacid (005N EDTA) Chloride nitrate and fluorine ionicactivity were measured with ion-selective electrodes usingOAKTON CE pHION Mod 510 Alkalinity was analyzedby titration method with sulfuric acid and sulfate wasmeasured by turbidimetricmethod using SpectrophotometerUV-VisibleMetrolab 1700 For a better detection limit arsenicwas analyzed by hydride generation atomic absorption spec-troscopy method (HGAAS) using hollow cathode lamps at1937 nm wavelength The instrument quantification limit forthis system was 5 120583g Lminus1 an intermediate precision of lessthanplusmn10was achieved All these analyses were performed atthe Laboratories of Quımica Analıtica Universidad Nacionaldel Chaco Austral Argentina
Total concentrations of 23 trace elements (Ag Al Ba BeB Cd Co Cr Cu Fe Mn Mo Ni P Pb S Sb Se Si Sr TiV and Zn) were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES) (PERKIN ELMER5100 DV axial solid state detector cross-flow nebulizerassociated with Scott Type chamber and AS type autosampler The equipment was linearly calibrated from 1 to100 120583g Lminus1 with custom certified standard solution (MerckICP Multielement Standard Solution XIII) 1198772 values ofcalibration curves were gt0995 and no trend was observed
in the residuals for all analyzedmetals Linearity was checkedafter every 10 samples using homemade control solutionIf the recovery was greater than plusmn10 the recalibrationwas performed for the concerned element Accuracy of theprocedure it has been tested by analyzing a certified referencematerial NIST SRM 1643 c ldquoTrace elements in waterrdquo Forthe studied elements bias ranged from 2 to 7 Precisionexpressed as intermediate precision was better than 9 forall analyzed elements
24 Statistical Analysis All statistical analysis of data includ-ing maximum and minimums means and medians wasperformed using the program STATGRAPHICS 51 (Statisti-cal Graphic Corporation Manugistics Inc Rockville USA)The software Rock Ware AqQA version 1151 was used toconstruct the Piper diagrams that depicted the groundwatertypes
3 Results and Discussion
31 Physicochemical Parameters The physicochemicalparameters determined in selecting 45 groundwater samplesare shown in Table 1 Well depth ranged between 5 and220m with average value of 23m The pH values of theassorted groundwater samples varied from 650 to 894 withaverage value of 754 indicating that the waters are generallyneutral to slightly alkalineThemeasured water temperaturesvary from 226 to 275∘C with an average of 238∘C
Major ion compositions of the analyzed groundwatersamples and themajor water types are shown in Table 1 Highnitrate concentrations (max = 200mg Lminus1) are present locallyin some wells probably due to anthropogenic influencesand a significant amount of NO
3
minus is thought to be fromevaporation However since the correlation between NO
3
minus
and Clminus is weak (1199032 = 004) evaporation is unlikely to be themost important cause of the high NO
3
minus concentrationsConsiderable spatial variation is observed for the dis-
tributions of major cations with dominance of Na+ (132to 5857mg Lminus1) K+ (210 to 110mg Lminus1) Ca2+ (140 to1100mg Lminus1) and Mg2+ (054 to 400mg Lminus1) The same vari-ation is observed for distribution of major anions with dom-inance of HCO
3
minus (median value 679mg Lminus1) Clminus (medianvalue 269mg Lminus1) and SO
4
2minus (median value 209mg Lminus1)Statistical parameters are shown in Table 2
Major ion compositions plotted on a Piper diagram(Figure 2) indicate that bicarbonate and chloride were thedominant anions followed by sulfate and that sodium wasthe prevalent cation The major water types in the samplesare presented in Table 1
ECvalues vary from069 and 249mS cmminus1with amedianvalue of 250mS cmminus1 and mean value of 527mS cmminus1This may be due to contribution of Na+ HCO
3
minus Clminus andSO4
2minus In saline groundwater chloride and sulfate are alsoimportant The most saline groundwater samples are of NandashCl type (maximum Clminus concentration 8193mg Lminus1 Tables 1and 2) although NandashSO
4
2minus types are also important (max-imum SO
4
2minus concentration 3485mg Lminus1) The most signifi-cant correlations are those of chloride versus EC and sodium
4 ISRN Environmental Chemistry
Table 1 Major ions composition of groundwater from the Comandante Fernandez Department Chaco
Sample ID Depth (m) pH EC (mS cmminus1) HCO3
minus Clminus SO4
2minus NO3
minus Na+ K+ Ca2+ Mg2+ Water typeM1 30 753 262 656 269 351 231 644 710 354 165 NandashHCO3
M44 11 707 250 723 450 901 561 223 303 132 646 CandashClM45 12 681 144 298 5674 263 424 459 286 1100 400 CandashClNd non detected All concentrations are expressed as mg Lminus1
ISRN Environmental Chemistry 5
Diagrama Piper
20
20
20
40
40
40
60
60
60
80
80
80
20
20
20
40
40
40
60
60
60
80
80
80
20
8080
20
40
6060
40
60
4040
60
80
2020
80
Mg (
)
Ca () Cl ()
Na + K ()
Na + K ()
SO4
+ Cl (
) Ca + Mg ()
HCO3
+ CO
3
SO4 ()
HCO3
+ CO
3(
)
Figure 2 Piper diagram showing the chemical compositions of groundwater samples
(1199032 = 091 1199032 = 069) and sulfate versus EC and sodium(1199032 = 062 1199032 = 061) which is related to the predominanceof sodium chloride types in groundwater with higher salinitySodium bicarbonate waters are related generally with lowsalinity samples in analyzed groundwater samples the ECshows poor correlation with HCO
3
minus (1199032 = 021)Results of chemical analysis show large variations in
chemical composition and also indicate the high salinity ofmany of the groundwater samples According to Larroza andFarina [19] the salinity of groundwater in the basin of theChaco region is due to the previous existence of a shallowsea of restricted environment which has left its salts thisgeographical feature called Paranaense Sea has originatedduring the Middle and Upper Miocene The extremelyheterogeneous values of EC from groundwater could beexplained by the local variation in sedimentary and hydro-geological characteristics [13] Moreover the evaporation inarid and semiarid zones favors the increase of salinity andalkalinity [15 22]
32 Total Arsenic and Fluoride Arsenic is classified as ahuman carcinogen (Type A) based on sufficient epidemio-logic evidence linking increased mortality from liver kidneybladder and lung cancers to drinking As-contaminatedwater[23] The provisional guideline value recommended by theWHO [5] for this carcinogenic contaminant in drinkingwater is 10 120583g Lminus1 and in Argentina this would be enforcedin 2017 [24] On the basis of this criterion only 9 (445)of groundwater source is within levels recommended forconsumption whereas about 73 (3345) of all analyzedsamples showed As values above 50 120583g Lminus1 (CAA) [25]Mean concentration of total arsenic in groundwater was213 120583g Lminus1 and maximum was 1990120583g Lminus1 (Table 2) Thehighest As concentrationwas found in groundwater collectedin sample M36 The presence of arsenic in the groundwatersamples collected from this region of Argentina is naturalthe local geology and rainfall have been shown to havemajor impact on the variations of As concentration ingroundwater
6 ISRN Environmental Chemistry
Table 2 Statistical summary of the chemistry of groundwater (major ions and trace elements 119899 = 45) from Comandante Fernandez Depart-ment Chaco Northeast Argentina
Parameter Mean Median Range 10th percentil 90th percentil Standard deviationDepth (m) 220 130 500ndash220 800 500 331pH 754 751 650ndash894 690 822 055EC (mScm) 527 250 069ndash249 099 134 628HCO
Different positive correlation were observed in ground-water between As versus HCO
3
minus and Na+ (1199032 = 075 1199032 =045) and a negative correlation was found between As andCa2+ (1199032 = minus005) It could be assumed that As is associatedwith NandashHCO
3
minus system related to feldspar dissolution [26]Based on values of pH found in groundwater of this region ofChaco including data reported from other sites of the region[1 13 27] it can be presumed that pH controls As mobility
The study made by Smedley et al [28] reveals that highlyAs(V)-contaminated groundwater in oxidizing environmentsthroughout the world are characterized by high concen-tration of HCO
3
minus (gt500mg Lminus1) and SO4
2minus (gt250mg Lminus1)and pH gt 750 Similar geochemical conditions occur in theChaco-Pampean plain like in the arid regions of Santiagodel Estero Cordoba y La Pampa [13 14 27] High As con-centrations are common and dominated by As(V) and thegroundwater have correspondingly high F concentrationsThese general characteristic are consistent with the analyzed
groundwater However arsenic speciation is not performedin the present study
On the other hand smaller quantities of fluoride ion inthe order of 1mg Lminus1 in ingested water are usually consideredto have a beneficial effect by lowering the rate of occurrenceof dental caries Excessive intake (gt15mg Lminus1) would resultsin pathological changes in teeth and bones such as mottlingof teeth or dental fluorosis along with metabolic changesreported on soft tissues such as thyroid reproductive organsbrain liver and kidneys [29]
TheWHOguideline value for F concentration in drinkingwater is 15mg Lminus1 [5] whereas the Codigo AlimentarioArgentino (CCA) [25] establishes a limit that varies accordingto the average temperature of the place (1mg Lminus1 for an aver-age temperature of 215∘C in the area under study) Thedistribution of F concentrations is heterogeneous and similarto As A positive correlation was observed between As andF with 1199032 = 050 The analyzed groundwater 31 (1445) of
ISRN Environmental Chemistry 7
the samples exceeded theWHO guideline value of 15mg Lminus1[5] About 47 of all analyzed samples showed F values above1mg Lminus1 recommended by CAA (Table 4) Similar correla-tions between As and F were also observed in groundwaterfrom neighboring Santiago del Estero [13] Santa Fe [14] andSalta Provinces [30]
In the same way as arsenic the F rich water is character-ized by high concentration of Na+ and low concentration ofCa2+ and Mg2+ (1199032 = 045 009 and 016 resp) Fluoride is ahighly reactive element that combines with other elements incovalent and ionic bonds It is mainly found in alkaline rocksand alkaline soils fluorite being the principal componentGomez et al [27] explain that the processes that could controlthe low relationship between F and Ca2+ and the positiverelationship between F and bicarbonate (1199032 = 024) would bethe balance equation relating calcite and fluorite when bothare in contact with water
As and other trace elements such as V Mo U and minorelements such as B and F are presumed to have their originalsource in volcanic ashes originated from the volcanismin the Andes (5ndash25 in the loess-type sediments of theChaco-Pampean plain) [9] The main components of thesesediments are feldspars quartz volcanic glass shards andminor amounts of muscovite and calcite The compositionof volcanic glass is typically rhyolitic containing a highconcentration of F As V and B among other trace elements[28]
33 Other Trace Elements A series of various trace elementsincluding Ag Al B Ba Be Cd Co Cr Cu Fe Mn MoNi P Pb S Sb Se Si Sr Ti V and Zn were also deter-mined in the studied groundwater The concentrations oftarget elements are summarized in Table 3 Among all 23target analytes concentrations exceeding the WHO recom-mended drinking water limits (in parentheses) were foundfor B (2400120583g Lminus1) Ba (700 120583g Lminus1) Cd (3 120583g Lminus1) and Sb(20120583g Lminus1) Table 4 shows the percentage of groundwatersamples exceeding these WHO and CAA elemental concen-tration guidelines On the other hand concentrations of SnCo Cu Ni S Se Sr V and Zn were very low Silver beryl-lium chrome selenium lead and titanium are not includ inTables 2 and 3 because these elements were never found aboverespective quantification limits
From the samples investigated only one (M45) showedelevated value of barium (1400 120583g Lminus1) than in the WHOdrinking water guideline (700 120583g Lminus1) with an average valueof 122120583g Lminus1 (Table 2)
In small quantities B is essential for healthy bones jointfunction and the metabolism of steroidal hormonesBoron deficiency seems to affect calcium and magnesiummetabolism and affects the composition structure andstrength of bone [31]The concentrations of boron (B) rangedfrom 1560 to 21910 120583g Lminus1 with an average of 4020120583g Lminus1(Table 2) Boron concentration in the 44 (2045) ofthe samples exceeds the WHO and 78 (3545) of thesamples exceeds the CAA standard limits for drinking water(Table 4) The highest concentration of boron was observedin sample M40 which is associated with the largest value
of EC (19371 120583S cmminus1) In general the presence of boron ingroundwater depends on its salinity (represented as EC) suchthat it increases with increasing salinity [32] In this studya positive correlation between EC and boron (1199032 = 064)suggests that boron might be associated with the salinity ofthese samplesHence the salinitymainly reflects the variationof Clminus concentration with a strong linear correlation(1199032 = 091) between EC and Clminus suggesting that the increaseof Clminus concentration contributes to increase in EC valueThehydraulic conductivity salinity type of clay sediments pHand temperature are the crucial factors that determine boronmobility in the groundwater system [32] Boron was stronglycorrelated with Na+ K+ Mg2+ Clminus SO
4
2minus HCO3
minus andAs probably due to their common origin The correlationbetween B and As is often observed in groundwater [1 13]
Our results indicate that approximately 31 of thegroundwater samples tested exceeded the CAA criteria of300 120583g Lminus1 for total Fe in drinking water The highest totalFe concentration (2000120583g Lminus1) appeared in sample M38 Ingeneral Fe concentrationwas low in the studied groundwatersamples only fourteen samples had higher Fe with a meanvalue of 276120583g Lminus1 and median value of 81 120583g Lminus1 On theother hand weaker correlation is observed between Fe andAsin groundwater (1199032 = 017) Moreover almost all groundwa-ter with high Fe concentration (gt300120583g Lminus1) contained totalAs concentration over 10 120583g Lminus1 (Table 3)
The concentration of dissolved Al varied between 600to 17380 120583g Lminus1 with a mean value of 561120583g Lminus1 (Table 2)A 16 (745) exceeded the 200120583g Lminus1 CAA drinking waterguideline However the mean concentration of Al decreasessignificantly down to 178120583g Lminus1 (median 985120583g Lminus1) if theanomalous of sample M24 is excluded Also Aluminumshows no correlation with As (1199032 = minus006)
Manganese exceeded the 100 120583g Lminus1 CAA drinking waterguideline value in 13 (645) of the samples (Tables 3 and4) The highest Mn concentration (3740 120583g Lminus1) was foundin sample M32 However the mean concentration of Mndecreases significantly from 152 to 700 120583g Lminus1 (median500120583g Lminus1) if the anomalous value of this sample is exclud-ed Manganese shows no correlation with As (1199032 = minus007)Mn is known as an essential element for human survivalserves as a catalyst and cofactor in many enzymatic processesinvolved in the synthesis of fatty acids and cholesterol Thechronic ingestion of Mn in drinking water is associated withneurologic damage [33] Moreover manganese is a knownmutagen [34]
Many samples have Fe Al and Mn concentrationsbelow detection limits and most have below CAA guidelinevalue However concentrations are higher in a few samples(Table 2) Smedley et al [1] suggest that at the pH of thegroundwater the high concentrations for these elements traceare most likely due to presence of colloidal particles As thegroundwater are oxidizing solubility of Fe Al andMnoxidesis low and concentrations of dissolved Fe Al and Mn aretherefore mostly low
The processes of dissolution and release from oxides andoxyhydroxides mainly Al Mn and Fe control the presence
8 ISRN Environmental Chemistry
Table3Tracee
lementcom
positionof
grou
ndwater
samples
from
theC
omandanteF
ernand
ezDepartm
entCh
aco
SampleID
As(to
t)F
Al
FeMn
BBa
Mo
SiV
Cd
SrCo
Ni
ZnCu
SP (
tot)
SbQL
500
010
100
100
500
200
100
100
500
100
300
250
100
100
100
100
0025
010
250
M1
500
190
110
600
500
1598
bql
126
bql
830
500
730
bql
bql
bql
bql
110
080
bql
M2
250
050
120
401
bql
310
156
bql
309
450
bql
420
bql
bql
bql
bql
200
030
bql
M3
100
180
900
160
300
875
bql
bql
bql
100
bql
691
bql
bql
300
bql
107
290
bql
M4
150
030
100
bql
bql
206
bql
bql
bql
220
bql
290
bql
bql
bql
bql
700
030
bql
M5
127
074
220
bql
900
811
791
420
227
119bq
l594
bql
bql
410
bql
020
090
bql
M6
580
080
110
bql
bql
297
100
bql
bql
440
bql
498
bql
bql
bql
bql
700
050
bql
M7
240
040
100
bql
bql
275
482
120
bql
430
bql
230
bql
bql
bql
bql
800
030
bql
M8
120
100
100
bql
600
2654
790
bql
2099
900
300
2012
bql
bql
bql
bql
110
080
bql
M9
178
198
130
550
700
1550
101
990
549
163
700
811
bql
bql
bql
630
700
080
900
M10
500
260
800
220
870
15070
bql
160
16570
390
400
4871
bql
bql
bql
bql
725
190
bql
M11
250
224
100
bql
600
1387
bql
140
480
230
bql
641
bql
bql
bql
bql
132
050
bql
M12
110
044
100
bql
194
500
620
bql
114530
bql
334
bql
100
bql
bql
130
060
bql
M13
952
110
110
bql
500
500
269
420
bql
760
400
683
bql
bql
bql
bql
100
030
300
M14
11615
0110
bql
500
665
bql
431
bql
650
500
540
bql
bql
bql
bql
700
070
bql
M15
310
050
102
500
500
2449
402
303
680
570
bql
521
bql
bql
bql
bql
490
060
bql
M16
290
040
130
150
500
255
518
bql
490
110
bql
362
bql
bql
bql
bql
260
030
bql
M17
830
120
100
bql
bql
1782
403
bql
3940
940
300
1427
bql
bql
bql
bql
113
020
300
M18
620
080
700
bql
182
734
bql
bql
2550
280
bql
2510
bql
bql
bql
bql
281
060
bql
M19
100
020
110
bql
500
298
144
bql
bql
300
bql
157
bql
bql
bql
bql
800
050
bql
M20
112
145
100
bql
bql
2316
220
109
4750
112
300
1390
bql
bql
bql
bdl
147
040
bql
M21
700
190
100
bql
254
2470
bql
112
353
280
bql
1361
bql
bql
bql
bql
415
890
bql
M22
100
020
100
bql
292
156
169
bql
bql
bql
bql
860
bql
bql
bql
bql
600
150
bql
M23
360
030
110
bql
bql
630
109
bql
bql
300
bql
225
bql
bql
bql
bql
500
070
900
M24
860
075
17380
310
296
21560
111
bql
1380
120
300
324
bql
bql
321
bql
010
080
bql
M25
770
120
2980
bql
521
6308
bql
bql
1647
220
Bql
bql
bql
100
2831
320
010
250
400
M26
100
340
600
110
bql
1800
150
210
150
198
300
150
bql
bql
bql
bql
006
180
bql
M27
214
420
600
855
bql
6890
bql
213
150
560
300
213
280
bql
670
280
006
110
bql
M28
100
340
600
428
bql
8450
bql
214
150
219
300
150
220
bql
bql
220
006
670
bql
M29
100
060
600
660
bql
6850
bql
208
150
100
300
150
bql
bql
670
bql
006
770
bql
M30
244
090
600
810
330
3050
185
210
150
547
300
150
bql
bql
240
bql
006
130
250
M31
770
340
280
1013
230
7290
bql
210
150
2646
300
322
bql
bql
bql
bql
030
030
bql
M32
700
010
210
286
3740
5080
632
209
150
bql
300
164
640
bql
110
640
020
230
300
M33
174
170
600
734
321
2790
690
210
7540
266
300
150
bql
bql
270
bql
Bql
220
bql
M34
317
030
360
575
240
1970
118
214
150
436
300
150
bql
bql
bql
bql
040
060
bql
M35
1073
030
600
194
bql
6340
301
205
150
1249
300
150
120
bql
490
120
006
030
300
M36
1990
425
600
510
135580
bql
210
150
251
300
288
240
bql
130
bql
006
530
300
M37
200
030
570
606
131290
113
210
150
387
300
203
240
100
160
670
060
050
bql
M38
150
190
600
2000
bql
3710
bql
210
150
380
300
200
950
bql
bql
bql
006
030
300
M39
200
050
600
300
bql
4830
140
210
150
104
300
200
bql
bql
bql
670
006
990
140
ISRN Environmental Chemistry 9
Table3Con
tinued
SampleID
As(to
t)F
Al
FeMn
BBa
Mo
SiV
Cd
SrCo
Ni
ZnCu
SP (
tot)
SbM40
200
050
600
689
bql
21910
bql
210
150
124
300
200
bql
bql
bql
240
006
130
300
M41
150
150
600
988
bql
21580
bql
210
150
176
300
302
bql
bql
bql
bql
006
110
300
M42
130
080
600
426
bql
1970
bql
210
150
345
300
369
180
bql
270
111
006
020
300
M43
150
140
600
700
431
1030
107
210
150
bql
300
bql
550
bql
220
270
006
080
bql
M44
100
120
600
800
bql
2600
289
210
150
191
300
bql
bql
bql
bql
bql
006
480
bql
M45
200
160
600
262
331
240
1400
210
150
350
300
bql
bql
bql
110490
006
230
bql
QLqu
antifi
ctionlim
itbq
lbello
wqu
antifi
catio
nlim
itallcon
centratio
nsaree
xpressed
as120583gLminus1excepted
forF
Sand
Pexpressedas
mgLminus1
10 ISRN Environmental Chemistry
Table 4 Risk-based drinking water criteria and the percentage ofgroundwater samples exceeding these criteria
NA not applicablelowastWHO World Health Organization have not established risk-based drink-ing water criteria for Al Ag Be Bi Co Fe Mn Mo Si Sr Ti V and ZnlowastlowastCAA Codigo Alimentario ArgentinolowastlowastlowastProvisional guideline value
and mobility of As and F in groundwater [1] Kim et al [35]suggested that the cocontamination of As and F observed inoxidizing aquifers in many countries is associated with thedesorption from the Fe-(hydr) oxides by the pH increasesThe correlations between As and F are generally very high inthose aquifers because the As released from Fe-(hydr) oxidesdoes not readily precipitate again in the oxidizing alkalinecondition This is consistent with our observations as manyof the samples show high pH values and moderate coefficientcorrelation value between As and F (1199032 = 050) Alsosolubility of Al minerals may be enhanced by the complex ofdissolved Al with F that is also released from volcanic glasses
Vanadium in groundwater ranged between lt100 (QL)and 2646 120583g Lminus1 The highest V concentration was found insample M31 (Table 2) Vanadium shows a moderated positivecorrelation with As (1199032 = 042) and is likely to be derivedfrom similar mineral sources (secondary Fe and Mn oxides)under the high pH conditions [1] Our results also indicatethat Mo in general appears in low concentrations (Table 3)Molybdenum is weakly correlated with As (1199032 = 020)
Gomez et al [27] suggest that V U B and Mo areenriched in volcanic materials and are mobilized as vanadatemolybdate borate and so forth under oxidizing conditionsAlternatively they are mobilized in alkaline solutions under
conditions of high pH and high HCO3
minus controlled bycarbonate reactions (eg the F may be forming anioniccomplexes with B Fe and Al)
Antimony (Sb) is ubiquity a GroupV of the periodic tableand is similar to As in aspects as chemical behavior andtoxicity to animals [5] The Sb concentrations in studiedsamples exceeded 20120583g Lminus1 WHO and CAA drinking waterguideline values in 45 (245) of the analyzed samples(Tables 3 and 4)
Cadmium reaches a maximum of 70120583g Lminus1 with mostsamples being less than 30 120583g Lminus1 As this element formscationic species in solution its mobilization is not favoredunder the alkaline conditions of the groundwater [1]
The presence of arsenic and heavy metals in the samplescollected from this region of Chaco in Argentina may be dueto local geochemical conditions that facilitate the transfer ofnaturally occurring arsenic from soil and sediment to thewaterThe people in the Comandante FernandezDepartmentmay be overexposed not only toAs but also to B CdMn andF Adverse health effects may appear in coming years Thisproblem is a serious concern for the local population
4 Conclusions
The results of the current study indicate that approximately91 of the groundwater samples used for consumptionby human and livestock from the Comandante FernandezDepartment (Chaco province Argentina) exceed the WHOprovisional guideline value of 10 120583g Lminus1 As recommended asa maximum allowable level in potable water
Evaporation potentiated in arid and semiarid zonefavors the increase of salinity and alkalinity the results is alow quality of the resource but is not conditioning the con-centration of As and F Hence factors other than evaporationsuch as desorption from metal oxides and possibly silicatereaction could be likely controlling As and F mobiliza-tion Furthermore arsenic associated trace elements may beabsorbed on the surface of iron and aluminum oxides andoxyhydroxides (hematite goethite Fe(OH)
3
and gibbsite)limiting the mobility of trace elements Groundwater withhigh pH values and high concentration of bicarbonate wouldfacilitate the dissolution of volcanic glass thus trace elementsmay enter groundwater cycles forming anionic complexes inalkaline solutions and acquiring great mobility
The hydrochemical trace in the region is characterizedby high salinity and high As and F concentrations whichis related to volcanism and hydrothermal activity from theAndes This association is often linked to presence of BCd Mo Mn and V indicating their common origin in thevolcanic glasses
Due to high As concentrations found in groundwaterserious health risk must be considered The population inthe area may be exposed to the chronic toxicological effectsof hydro arsenicism and fluorosis increasing the risks ofcontracting other diseases derived from them Since thegroundwater studied here constitutes the principal source ofdrinking water in the zone mitigation efforts should not belimited to As health risks from other toxic elements presentin drinking water must also be addressed in this region
ISRN Environmental Chemistry 11
Conflict of Interest
The authors declare that there is no conflict of interestsregarding the publication of this paper Its publication isapproved by all authors and tacitly or explicitly by the respon-sible authorities where the work was carried out and that ifaccepted it will not be published elsewhere in the same formin English or in any other language including electronicallywithout the written consent of the copyright-holder
Acknowledgments
This work was supported with funds from PI 3600005 Uni-versidad Nacional del Chaco Austral (UNCAus) Patricia SBlanes thanks the National Academy of Exact Physic andNatural Sciences for granting a PhD fellowship
References
[1] P L Smedley H B Nicolli DM JMacdonald A J Barros andJ O Tullio ldquoHydrogeochemistry of arsenic and other inorganicconstituents in groundwaters from La Pampa ArgentinardquoApplied Geochemistry vol 17 no 3 pp 259ndash284 2002
[2] S Muhammad M T Shah and S Khan ldquoHealth risk assess-ment of heavy metals and their source apportionment in drink-ingwater of Kohistan region northern PakistanrdquoMicrochemicalJournal vol 98 no 2 pp 334ndash343 2011
[3] S S Farıas V A Casa C Vazquez L Ferpozzi G N Pucci andI M Cohen ldquoNatural contamination with arsenic and othertrace elements in ground waters of Argentine Pampean PlainrdquoScience of the Total Environment vol 309 no 1ndash3 pp 187ndash1992003
[4] L Jarup ldquoHazards of heavy metal contaminationrdquo British Med-ical Bulletin vol 68 pp 167ndash182 2003
[5] World Health Organization (WHO) ldquoRecommendationsrdquo inGuidelines for Drinking Water Quality vol 1 Geneva Switzer-land 4th edition 2011
[6] C Hopenhayn ldquoArsenic in drinking water impact on humanhealthrdquo Elements vol 2 no 2 pp 103ndash107 2006
[7] S H Lamm and M B Kruse ldquoArsenic ingestion and bladdercancermortalitymdashwhat do the dose-response relationships sug-gest aboutmechanismrdquoHumanandEcological RiskAssessmentvol 11 no 2 pp 433ndash450 2005
[8] C-HWang C K Hsiao C-L Chen et al ldquoA review of the epi-demiologic literature on the role of environmental arsenicexposure and cardiovascular diseasesrdquo Toxicology and AppliedPharmacology vol 222 no 3 pp 315ndash326 2007
[9] J Bundschuh M I Litter F Parvez et al ldquoOne century ofarsenic exposure in Latin America a review of history andoccurrence from 14 countriesrdquo Science of the Total Environmentvol 429 pp 2ndash35 2012
[10] M T Alarcon-Herrera J Bundschuh B Nath et al ldquoCo-occurrence of arsenic and fluoride in groundwater of semi-aridregions in Latin America genesis mobility and remediationrdquoJournal of Hazardous Materials 2012
[11] E E Buchhamer P S Blanes RM Osicka andM C GimenezldquoEnvironmental risk assessment of arsenic and fluoride in thechaco province argentina research advancesrdquo Journal of Toxi-cology and Environmental Health A vol 75 no 22-23 pp 1437ndash1450 2012
[12] A Cabrera M Blarasin E Matteoda G Villalva and M LGomez ldquoComposicion quımica del agua subterranea en el surde Cordoba lınea de base hidroquımica o fondo natural enreferencia a arsenico y fluorrdquo in Aguas Superficiales y Sub-terraneas en el sur ae Cordoba Una Perspectiva GeoambientalM Blarasin S Degiovanni A Cabera and M Villegas Edspp 81ndash90 Universidad Nacional de Rıo Cuarto Rıo CuartoArgentina 2005
[13] P Bhattacharya M Claesson J Bundschuh et al ldquoDistributionand mobility of arsenic in the Rıo Dulce alluvial aquifers inSantiago del Estero Province Argentinardquo Science of the TotalEnvironment vol 358 no 1ndash3 pp 97ndash120 2006
[14] B Nicolli O C Tujchneider M C Paris M Blanco and A JBarros ldquoMovilidad del arsenico y oligoelementos asociados enaguas subterraneas del centro-norte de la provincia de Santa FeArgentinardquo in Proceedings of the Presencia de Fluor y Arsenicoen Aguas Subterraneas VI Congreso Hidrogeologico ArgentinoG Galindo J L Fernandez Turiel and A Storniolo Eds pp81ndash90 Santa Rosa La Pampa Argentina 2009
[15] H B Nicolli A Tineo J W Garcıa C M Falcon and PL Smedley ldquoMobilization of arsenic and other trace elementof health concern in groundwater from the Salı River BasinTucuman Province Argentinardquo Environmental Geochemistryand Health vol 34 no 2 pp 251ndash262 2012
[16] RMOsicka N Agullo C Herrera Ahuad andMC GimenezldquoEvaluacion de las concentraciones de fluoruro y arsenico enlas aguas subterraneas del Domo Central de la provincia delChacordquo Comunicaciones Cientıficas y Tecnologicas Univer-sidad Nacional del Nordeste 2002 httpwwwunneeduarunneviejaWebcytcyt200208-ExactasE-049pdf
[17] C E Fiorentino J D Paoloni M E Sequeira and P ArosteguyldquoThe presence of vanadium in groundwater of southeasternextreme the pampean region Argentina Relationship withother chemical elementsrdquo Journal of Contaminant Hydrologyvol 93 no 1ndash4 pp 122ndash129 2007
[18] P Sprechmann F G Acenaloza C Gaucher A C R Nogueiraand M J Perez ldquoTrasgresion Paranaense paleoestuario deltethys del miocenomedio yo superior en Sudamericardquo in Con-greso Latinoamericano de Geologıa Montevideo-UruguayAbstracts 1 CDRoom pp 10ndash15 Sociedad Latinoamericana deGeologıa 2001
[19] F Larroza and L S Farina ldquoCaracterizacion hidrogeologica delsistema acuıfero Yrenda (SAY) en Paraguay recurso compar-tido con y Boliviardquo in Proceedings of the IV Congreso Argentinode Hidrogeologıa TOMO II Argentinarıo Cuarto CordobaArgentina 2005
[20] E Popolizio P Y Serra and G O Hort ldquoLa clasificaciontaxonomica del Chacordquo Centro de Geociencia Aplicada vol 3no 1 pp 11ndash32 1980
[21] INTA ldquoInstituto Nacional de Tecnologıa AgropecuariardquoAgrometeorologıa httpwwwintagovarsaenzpemeteorolo-giameteorologiahtm
[22] M G Garcıa O Sracek D S Fernandez andM D V HidalgoldquoFactors affecting arsenic concentration in groundwaters fromNorthwestern Chaco-Pampean Plain Argentinardquo Environmen-tal Geology vol 52 no 7 pp 1261ndash1275 2007
[23] US Environmental Protection Agency ( EPA) ldquoArsenic Inor-ganic United States Environmental Protection Agency Inte-grated Risk Information System (IRIS) (CASRN 7440-38-2)rdquo1998 httpwwwepagovirissubst0278htm
12 ISRN Environmental Chemistry
[24] Comision Nacional de Alimentos (CONAL) Acta Nž 93Reunion Ordinaria 3011 y 0112-2011 (Prorroga Art 982 y 983del CAA)
[25] CAA (Codigo Alimentario Argentino) Cap XII Bebidashıdricas agua y agua gasificada In Codigo Alimentario Argen-tino modificatoria del Art 982 (Res 682007 y 1962007) Ley18 284 Buenos Aires Argentina 2007 httpwwwanmatgovarCODIGOACapitulo XII Agua 2007-05pdf
[26] J L Fernandez Turiel G GalindoM A Parada D GimenoMGarcıa-Valles and J Saavedra ldquoEstado actual del conocimientosobre el arsenico en el agua de Argentina y Chile origenmovilidad y transporterdquo inArsenico en Agua Origen movilidady tratamiento II Seminario Hispano-Latinoamericano sobreTemas Actuales de Hidrologıa Subterranea y IV Congreso Hidro-geologico Argentino pp 1ndash22 Rıo Cuarto Argentina 2005
[27] M L Gomez M T Blarasin and D E Martınez ldquoArsenic andfluoride in a loess aquifer in the central area of Argentinardquo Envi-ronmental Geology vol 57 no 1 pp 143ndash155 2009
[28] P L Smedley D G Kinniburgh D M J Macdonald et alldquoArsenic associations in sediments from the loess aquifer of LaPampa Argentinardquo Applied Geochemistry vol 20 no 5 pp989ndash1016 2005
[29] D L Ozsvath ldquoFluoride and environmental health a reviewrdquoReviews in Environmental Science and Biotechnology vol 8 no1 pp 59ndash79 2009
[30] E M Farfan Torres P M Naranjo A Boemo I Lomnicziand L Lorenzo ldquoDistribution of arsenic in groundwater in theChaco Salteno Argentinardquo in Workshop on as Distribution inIbero-America M I Litter Ed CyTED IBEROARSENAbstractBook pp 57ndash60 2006
[31] httpwwwjctoniccomincludemineralsboronhtm[32] M A Halim R K Majumder S A Nessa et al ldquoEvaluation
of processes controlling the geochemical constituents in deepgroundwater in Bangladesh spatial variability on arsenic andboron enrichmentrdquo Journal of HazardousMaterials vol 180 no1ndash3 pp 50ndash62 2010
[33] J BuschmannM Berg C Stengel andM L Sampson ldquoArsenicand manganese contamination of drinking water resources inCambodia coincidence of risk areaswith low relief topographyrdquoEnvironmental Science and Technology vol 41 no 7 pp 2146ndash2152 2007
[34] R A Beckman A S Mildvan and L A Loeb ldquoOn the fidelityof DNA replication manganese mutagenesis in vitrordquo Biochem-istry vol 24 no 21 pp 5810ndash5817 1985
[35] S-H Kim K Kim K-S Ko Y Kim and K-S Lee ldquoCo-con-tamination of arsenic andfluoride in the groundwater of uncon-solidated aquifers under reducing environmentsrdquoChemospherevol 87 no 8 pp 851ndash856 2012
22 Sampling and Analysis Forty-five groundwater sampleswere collected during MayndashOctober 2010 (a dry season)in rural and suburbs areas of the Comandante FernandezDepartment (Chaco Province) (Figure 1) Each sample hasbeen collected from each tube well Latitude and longitude ofthese tube wells were determined using a Garmin eTrex Leg-end Global Positioning System (Garmin Ltd UK) Specificwell information that is the depth of the well was obtainedfrom its owner The sampling points were selected takinginto account their spatial distribution in the area in order toobtain an accurately representative hydrochemistry
For all analyses cleaning and sampling procedureinvolved deionized distilled water (DDW) produced byMilliQ water (Millipore Elix 5) and high-purity solvents Allglassware and polyethylene bottles were kept in 10 (vv)HNO
3
(Merk 65) for 24 hours rinsed out with DDIand dried in a stove All tube-wells samples were collectedafter 3min flushing filtered through 045120583m membranefilters and transferred to three different polyethylene bottlesto undertake different analysis Samples for major cationsanalysis (Ca2+Mg2+ Na+ andK+) and total Aswere acidifiedwith 006M HCl For trace metals analysis samples wereacidified to pHlt 2 by addition of ultrapure nitric acid (Fluka)No acidified fractions were collected without headspaces inthe sample bottles for measurements of anions such as ClminusSO4
2minus NO3
minus F and alkalinity All the samples were kept at4∘C until analysis
23 Groundwater Analyses The physical parameters likewater temperature (T) pH and electrical conductivity (EC)were measured in situ by using a HANNAHI991301 PortablePHECTDSTemperature Meter Na+ and K+ were deter-mined by emission flame spectrometry (JENWAY PFP7)and Ca2+ and Mg2+ concentrations were determined bycomplexometric titration using ethylenediaminetetraaceticacid (005N EDTA) Chloride nitrate and fluorine ionicactivity were measured with ion-selective electrodes usingOAKTON CE pHION Mod 510 Alkalinity was analyzedby titration method with sulfuric acid and sulfate wasmeasured by turbidimetricmethod using SpectrophotometerUV-VisibleMetrolab 1700 For a better detection limit arsenicwas analyzed by hydride generation atomic absorption spec-troscopy method (HGAAS) using hollow cathode lamps at1937 nm wavelength The instrument quantification limit forthis system was 5 120583g Lminus1 an intermediate precision of lessthanplusmn10was achieved All these analyses were performed atthe Laboratories of Quımica Analıtica Universidad Nacionaldel Chaco Austral Argentina
Total concentrations of 23 trace elements (Ag Al Ba BeB Cd Co Cr Cu Fe Mn Mo Ni P Pb S Sb Se Si Sr TiV and Zn) were determined by inductively coupled plasma-optical emission spectrometry (ICP-OES) (PERKIN ELMER5100 DV axial solid state detector cross-flow nebulizerassociated with Scott Type chamber and AS type autosampler The equipment was linearly calibrated from 1 to100 120583g Lminus1 with custom certified standard solution (MerckICP Multielement Standard Solution XIII) 1198772 values ofcalibration curves were gt0995 and no trend was observed
in the residuals for all analyzedmetals Linearity was checkedafter every 10 samples using homemade control solutionIf the recovery was greater than plusmn10 the recalibrationwas performed for the concerned element Accuracy of theprocedure it has been tested by analyzing a certified referencematerial NIST SRM 1643 c ldquoTrace elements in waterrdquo Forthe studied elements bias ranged from 2 to 7 Precisionexpressed as intermediate precision was better than 9 forall analyzed elements
24 Statistical Analysis All statistical analysis of data includ-ing maximum and minimums means and medians wasperformed using the program STATGRAPHICS 51 (Statisti-cal Graphic Corporation Manugistics Inc Rockville USA)The software Rock Ware AqQA version 1151 was used toconstruct the Piper diagrams that depicted the groundwatertypes
3 Results and Discussion
31 Physicochemical Parameters The physicochemicalparameters determined in selecting 45 groundwater samplesare shown in Table 1 Well depth ranged between 5 and220m with average value of 23m The pH values of theassorted groundwater samples varied from 650 to 894 withaverage value of 754 indicating that the waters are generallyneutral to slightly alkalineThemeasured water temperaturesvary from 226 to 275∘C with an average of 238∘C
Major ion compositions of the analyzed groundwatersamples and themajor water types are shown in Table 1 Highnitrate concentrations (max = 200mg Lminus1) are present locallyin some wells probably due to anthropogenic influencesand a significant amount of NO
3
minus is thought to be fromevaporation However since the correlation between NO
3
minus
and Clminus is weak (1199032 = 004) evaporation is unlikely to be themost important cause of the high NO
3
minus concentrationsConsiderable spatial variation is observed for the dis-
tributions of major cations with dominance of Na+ (132to 5857mg Lminus1) K+ (210 to 110mg Lminus1) Ca2+ (140 to1100mg Lminus1) and Mg2+ (054 to 400mg Lminus1) The same vari-ation is observed for distribution of major anions with dom-inance of HCO
3
minus (median value 679mg Lminus1) Clminus (medianvalue 269mg Lminus1) and SO
4
2minus (median value 209mg Lminus1)Statistical parameters are shown in Table 2
Major ion compositions plotted on a Piper diagram(Figure 2) indicate that bicarbonate and chloride were thedominant anions followed by sulfate and that sodium wasthe prevalent cation The major water types in the samplesare presented in Table 1
ECvalues vary from069 and 249mS cmminus1with amedianvalue of 250mS cmminus1 and mean value of 527mS cmminus1This may be due to contribution of Na+ HCO
3
minus Clminus andSO4
2minus In saline groundwater chloride and sulfate are alsoimportant The most saline groundwater samples are of NandashCl type (maximum Clminus concentration 8193mg Lminus1 Tables 1and 2) although NandashSO
4
2minus types are also important (max-imum SO
4
2minus concentration 3485mg Lminus1) The most signifi-cant correlations are those of chloride versus EC and sodium
4 ISRN Environmental Chemistry
Table 1 Major ions composition of groundwater from the Comandante Fernandez Department Chaco
Sample ID Depth (m) pH EC (mS cmminus1) HCO3
minus Clminus SO4
2minus NO3
minus Na+ K+ Ca2+ Mg2+ Water typeM1 30 753 262 656 269 351 231 644 710 354 165 NandashHCO3
M44 11 707 250 723 450 901 561 223 303 132 646 CandashClM45 12 681 144 298 5674 263 424 459 286 1100 400 CandashClNd non detected All concentrations are expressed as mg Lminus1
ISRN Environmental Chemistry 5
Diagrama Piper
20
20
20
40
40
40
60
60
60
80
80
80
20
20
20
40
40
40
60
60
60
80
80
80
20
8080
20
40
6060
40
60
4040
60
80
2020
80
Mg (
)
Ca () Cl ()
Na + K ()
Na + K ()
SO4
+ Cl (
) Ca + Mg ()
HCO3
+ CO
3
SO4 ()
HCO3
+ CO
3(
)
Figure 2 Piper diagram showing the chemical compositions of groundwater samples
(1199032 = 091 1199032 = 069) and sulfate versus EC and sodium(1199032 = 062 1199032 = 061) which is related to the predominanceof sodium chloride types in groundwater with higher salinitySodium bicarbonate waters are related generally with lowsalinity samples in analyzed groundwater samples the ECshows poor correlation with HCO
3
minus (1199032 = 021)Results of chemical analysis show large variations in
chemical composition and also indicate the high salinity ofmany of the groundwater samples According to Larroza andFarina [19] the salinity of groundwater in the basin of theChaco region is due to the previous existence of a shallowsea of restricted environment which has left its salts thisgeographical feature called Paranaense Sea has originatedduring the Middle and Upper Miocene The extremelyheterogeneous values of EC from groundwater could beexplained by the local variation in sedimentary and hydro-geological characteristics [13] Moreover the evaporation inarid and semiarid zones favors the increase of salinity andalkalinity [15 22]
32 Total Arsenic and Fluoride Arsenic is classified as ahuman carcinogen (Type A) based on sufficient epidemio-logic evidence linking increased mortality from liver kidneybladder and lung cancers to drinking As-contaminatedwater[23] The provisional guideline value recommended by theWHO [5] for this carcinogenic contaminant in drinkingwater is 10 120583g Lminus1 and in Argentina this would be enforcedin 2017 [24] On the basis of this criterion only 9 (445)of groundwater source is within levels recommended forconsumption whereas about 73 (3345) of all analyzedsamples showed As values above 50 120583g Lminus1 (CAA) [25]Mean concentration of total arsenic in groundwater was213 120583g Lminus1 and maximum was 1990120583g Lminus1 (Table 2) Thehighest As concentrationwas found in groundwater collectedin sample M36 The presence of arsenic in the groundwatersamples collected from this region of Argentina is naturalthe local geology and rainfall have been shown to havemajor impact on the variations of As concentration ingroundwater
6 ISRN Environmental Chemistry
Table 2 Statistical summary of the chemistry of groundwater (major ions and trace elements 119899 = 45) from Comandante Fernandez Depart-ment Chaco Northeast Argentina
Parameter Mean Median Range 10th percentil 90th percentil Standard deviationDepth (m) 220 130 500ndash220 800 500 331pH 754 751 650ndash894 690 822 055EC (mScm) 527 250 069ndash249 099 134 628HCO
Different positive correlation were observed in ground-water between As versus HCO
3
minus and Na+ (1199032 = 075 1199032 =045) and a negative correlation was found between As andCa2+ (1199032 = minus005) It could be assumed that As is associatedwith NandashHCO
3
minus system related to feldspar dissolution [26]Based on values of pH found in groundwater of this region ofChaco including data reported from other sites of the region[1 13 27] it can be presumed that pH controls As mobility
The study made by Smedley et al [28] reveals that highlyAs(V)-contaminated groundwater in oxidizing environmentsthroughout the world are characterized by high concen-tration of HCO
3
minus (gt500mg Lminus1) and SO4
2minus (gt250mg Lminus1)and pH gt 750 Similar geochemical conditions occur in theChaco-Pampean plain like in the arid regions of Santiagodel Estero Cordoba y La Pampa [13 14 27] High As con-centrations are common and dominated by As(V) and thegroundwater have correspondingly high F concentrationsThese general characteristic are consistent with the analyzed
groundwater However arsenic speciation is not performedin the present study
On the other hand smaller quantities of fluoride ion inthe order of 1mg Lminus1 in ingested water are usually consideredto have a beneficial effect by lowering the rate of occurrenceof dental caries Excessive intake (gt15mg Lminus1) would resultsin pathological changes in teeth and bones such as mottlingof teeth or dental fluorosis along with metabolic changesreported on soft tissues such as thyroid reproductive organsbrain liver and kidneys [29]
TheWHOguideline value for F concentration in drinkingwater is 15mg Lminus1 [5] whereas the Codigo AlimentarioArgentino (CCA) [25] establishes a limit that varies accordingto the average temperature of the place (1mg Lminus1 for an aver-age temperature of 215∘C in the area under study) Thedistribution of F concentrations is heterogeneous and similarto As A positive correlation was observed between As andF with 1199032 = 050 The analyzed groundwater 31 (1445) of
ISRN Environmental Chemistry 7
the samples exceeded theWHO guideline value of 15mg Lminus1[5] About 47 of all analyzed samples showed F values above1mg Lminus1 recommended by CAA (Table 4) Similar correla-tions between As and F were also observed in groundwaterfrom neighboring Santiago del Estero [13] Santa Fe [14] andSalta Provinces [30]
In the same way as arsenic the F rich water is character-ized by high concentration of Na+ and low concentration ofCa2+ and Mg2+ (1199032 = 045 009 and 016 resp) Fluoride is ahighly reactive element that combines with other elements incovalent and ionic bonds It is mainly found in alkaline rocksand alkaline soils fluorite being the principal componentGomez et al [27] explain that the processes that could controlthe low relationship between F and Ca2+ and the positiverelationship between F and bicarbonate (1199032 = 024) would bethe balance equation relating calcite and fluorite when bothare in contact with water
As and other trace elements such as V Mo U and minorelements such as B and F are presumed to have their originalsource in volcanic ashes originated from the volcanismin the Andes (5ndash25 in the loess-type sediments of theChaco-Pampean plain) [9] The main components of thesesediments are feldspars quartz volcanic glass shards andminor amounts of muscovite and calcite The compositionof volcanic glass is typically rhyolitic containing a highconcentration of F As V and B among other trace elements[28]
33 Other Trace Elements A series of various trace elementsincluding Ag Al B Ba Be Cd Co Cr Cu Fe Mn MoNi P Pb S Sb Se Si Sr Ti V and Zn were also deter-mined in the studied groundwater The concentrations oftarget elements are summarized in Table 3 Among all 23target analytes concentrations exceeding the WHO recom-mended drinking water limits (in parentheses) were foundfor B (2400120583g Lminus1) Ba (700 120583g Lminus1) Cd (3 120583g Lminus1) and Sb(20120583g Lminus1) Table 4 shows the percentage of groundwatersamples exceeding these WHO and CAA elemental concen-tration guidelines On the other hand concentrations of SnCo Cu Ni S Se Sr V and Zn were very low Silver beryl-lium chrome selenium lead and titanium are not includ inTables 2 and 3 because these elements were never found aboverespective quantification limits
From the samples investigated only one (M45) showedelevated value of barium (1400 120583g Lminus1) than in the WHOdrinking water guideline (700 120583g Lminus1) with an average valueof 122120583g Lminus1 (Table 2)
In small quantities B is essential for healthy bones jointfunction and the metabolism of steroidal hormonesBoron deficiency seems to affect calcium and magnesiummetabolism and affects the composition structure andstrength of bone [31]The concentrations of boron (B) rangedfrom 1560 to 21910 120583g Lminus1 with an average of 4020120583g Lminus1(Table 2) Boron concentration in the 44 (2045) ofthe samples exceeds the WHO and 78 (3545) of thesamples exceeds the CAA standard limits for drinking water(Table 4) The highest concentration of boron was observedin sample M40 which is associated with the largest value
of EC (19371 120583S cmminus1) In general the presence of boron ingroundwater depends on its salinity (represented as EC) suchthat it increases with increasing salinity [32] In this studya positive correlation between EC and boron (1199032 = 064)suggests that boron might be associated with the salinity ofthese samplesHence the salinitymainly reflects the variationof Clminus concentration with a strong linear correlation(1199032 = 091) between EC and Clminus suggesting that the increaseof Clminus concentration contributes to increase in EC valueThehydraulic conductivity salinity type of clay sediments pHand temperature are the crucial factors that determine boronmobility in the groundwater system [32] Boron was stronglycorrelated with Na+ K+ Mg2+ Clminus SO
4
2minus HCO3
minus andAs probably due to their common origin The correlationbetween B and As is often observed in groundwater [1 13]
Our results indicate that approximately 31 of thegroundwater samples tested exceeded the CAA criteria of300 120583g Lminus1 for total Fe in drinking water The highest totalFe concentration (2000120583g Lminus1) appeared in sample M38 Ingeneral Fe concentrationwas low in the studied groundwatersamples only fourteen samples had higher Fe with a meanvalue of 276120583g Lminus1 and median value of 81 120583g Lminus1 On theother hand weaker correlation is observed between Fe andAsin groundwater (1199032 = 017) Moreover almost all groundwa-ter with high Fe concentration (gt300120583g Lminus1) contained totalAs concentration over 10 120583g Lminus1 (Table 3)
The concentration of dissolved Al varied between 600to 17380 120583g Lminus1 with a mean value of 561120583g Lminus1 (Table 2)A 16 (745) exceeded the 200120583g Lminus1 CAA drinking waterguideline However the mean concentration of Al decreasessignificantly down to 178120583g Lminus1 (median 985120583g Lminus1) if theanomalous of sample M24 is excluded Also Aluminumshows no correlation with As (1199032 = minus006)
Manganese exceeded the 100 120583g Lminus1 CAA drinking waterguideline value in 13 (645) of the samples (Tables 3 and4) The highest Mn concentration (3740 120583g Lminus1) was foundin sample M32 However the mean concentration of Mndecreases significantly from 152 to 700 120583g Lminus1 (median500120583g Lminus1) if the anomalous value of this sample is exclud-ed Manganese shows no correlation with As (1199032 = minus007)Mn is known as an essential element for human survivalserves as a catalyst and cofactor in many enzymatic processesinvolved in the synthesis of fatty acids and cholesterol Thechronic ingestion of Mn in drinking water is associated withneurologic damage [33] Moreover manganese is a knownmutagen [34]
Many samples have Fe Al and Mn concentrationsbelow detection limits and most have below CAA guidelinevalue However concentrations are higher in a few samples(Table 2) Smedley et al [1] suggest that at the pH of thegroundwater the high concentrations for these elements traceare most likely due to presence of colloidal particles As thegroundwater are oxidizing solubility of Fe Al andMnoxidesis low and concentrations of dissolved Fe Al and Mn aretherefore mostly low
The processes of dissolution and release from oxides andoxyhydroxides mainly Al Mn and Fe control the presence
8 ISRN Environmental Chemistry
Table3Tracee
lementcom
positionof
grou
ndwater
samples
from
theC
omandanteF
ernand
ezDepartm
entCh
aco
SampleID
As(to
t)F
Al
FeMn
BBa
Mo
SiV
Cd
SrCo
Ni
ZnCu
SP (
tot)
SbQL
500
010
100
100
500
200
100
100
500
100
300
250
100
100
100
100
0025
010
250
M1
500
190
110
600
500
1598
bql
126
bql
830
500
730
bql
bql
bql
bql
110
080
bql
M2
250
050
120
401
bql
310
156
bql
309
450
bql
420
bql
bql
bql
bql
200
030
bql
M3
100
180
900
160
300
875
bql
bql
bql
100
bql
691
bql
bql
300
bql
107
290
bql
M4
150
030
100
bql
bql
206
bql
bql
bql
220
bql
290
bql
bql
bql
bql
700
030
bql
M5
127
074
220
bql
900
811
791
420
227
119bq
l594
bql
bql
410
bql
020
090
bql
M6
580
080
110
bql
bql
297
100
bql
bql
440
bql
498
bql
bql
bql
bql
700
050
bql
M7
240
040
100
bql
bql
275
482
120
bql
430
bql
230
bql
bql
bql
bql
800
030
bql
M8
120
100
100
bql
600
2654
790
bql
2099
900
300
2012
bql
bql
bql
bql
110
080
bql
M9
178
198
130
550
700
1550
101
990
549
163
700
811
bql
bql
bql
630
700
080
900
M10
500
260
800
220
870
15070
bql
160
16570
390
400
4871
bql
bql
bql
bql
725
190
bql
M11
250
224
100
bql
600
1387
bql
140
480
230
bql
641
bql
bql
bql
bql
132
050
bql
M12
110
044
100
bql
194
500
620
bql
114530
bql
334
bql
100
bql
bql
130
060
bql
M13
952
110
110
bql
500
500
269
420
bql
760
400
683
bql
bql
bql
bql
100
030
300
M14
11615
0110
bql
500
665
bql
431
bql
650
500
540
bql
bql
bql
bql
700
070
bql
M15
310
050
102
500
500
2449
402
303
680
570
bql
521
bql
bql
bql
bql
490
060
bql
M16
290
040
130
150
500
255
518
bql
490
110
bql
362
bql
bql
bql
bql
260
030
bql
M17
830
120
100
bql
bql
1782
403
bql
3940
940
300
1427
bql
bql
bql
bql
113
020
300
M18
620
080
700
bql
182
734
bql
bql
2550
280
bql
2510
bql
bql
bql
bql
281
060
bql
M19
100
020
110
bql
500
298
144
bql
bql
300
bql
157
bql
bql
bql
bql
800
050
bql
M20
112
145
100
bql
bql
2316
220
109
4750
112
300
1390
bql
bql
bql
bdl
147
040
bql
M21
700
190
100
bql
254
2470
bql
112
353
280
bql
1361
bql
bql
bql
bql
415
890
bql
M22
100
020
100
bql
292
156
169
bql
bql
bql
bql
860
bql
bql
bql
bql
600
150
bql
M23
360
030
110
bql
bql
630
109
bql
bql
300
bql
225
bql
bql
bql
bql
500
070
900
M24
860
075
17380
310
296
21560
111
bql
1380
120
300
324
bql
bql
321
bql
010
080
bql
M25
770
120
2980
bql
521
6308
bql
bql
1647
220
Bql
bql
bql
100
2831
320
010
250
400
M26
100
340
600
110
bql
1800
150
210
150
198
300
150
bql
bql
bql
bql
006
180
bql
M27
214
420
600
855
bql
6890
bql
213
150
560
300
213
280
bql
670
280
006
110
bql
M28
100
340
600
428
bql
8450
bql
214
150
219
300
150
220
bql
bql
220
006
670
bql
M29
100
060
600
660
bql
6850
bql
208
150
100
300
150
bql
bql
670
bql
006
770
bql
M30
244
090
600
810
330
3050
185
210
150
547
300
150
bql
bql
240
bql
006
130
250
M31
770
340
280
1013
230
7290
bql
210
150
2646
300
322
bql
bql
bql
bql
030
030
bql
M32
700
010
210
286
3740
5080
632
209
150
bql
300
164
640
bql
110
640
020
230
300
M33
174
170
600
734
321
2790
690
210
7540
266
300
150
bql
bql
270
bql
Bql
220
bql
M34
317
030
360
575
240
1970
118
214
150
436
300
150
bql
bql
bql
bql
040
060
bql
M35
1073
030
600
194
bql
6340
301
205
150
1249
300
150
120
bql
490
120
006
030
300
M36
1990
425
600
510
135580
bql
210
150
251
300
288
240
bql
130
bql
006
530
300
M37
200
030
570
606
131290
113
210
150
387
300
203
240
100
160
670
060
050
bql
M38
150
190
600
2000
bql
3710
bql
210
150
380
300
200
950
bql
bql
bql
006
030
300
M39
200
050
600
300
bql
4830
140
210
150
104
300
200
bql
bql
bql
670
006
990
140
ISRN Environmental Chemistry 9
Table3Con
tinued
SampleID
As(to
t)F
Al
FeMn
BBa
Mo
SiV
Cd
SrCo
Ni
ZnCu
SP (
tot)
SbM40
200
050
600
689
bql
21910
bql
210
150
124
300
200
bql
bql
bql
240
006
130
300
M41
150
150
600
988
bql
21580
bql
210
150
176
300
302
bql
bql
bql
bql
006
110
300
M42
130
080
600
426
bql
1970
bql
210
150
345
300
369
180
bql
270
111
006
020
300
M43
150
140
600
700
431
1030
107
210
150
bql
300
bql
550
bql
220
270
006
080
bql
M44
100
120
600
800
bql
2600
289
210
150
191
300
bql
bql
bql
bql
bql
006
480
bql
M45
200
160
600
262
331
240
1400
210
150
350
300
bql
bql
bql
110490
006
230
bql
QLqu
antifi
ctionlim
itbq
lbello
wqu
antifi
catio
nlim
itallcon
centratio
nsaree
xpressed
as120583gLminus1excepted
forF
Sand
Pexpressedas
mgLminus1
10 ISRN Environmental Chemistry
Table 4 Risk-based drinking water criteria and the percentage ofgroundwater samples exceeding these criteria
NA not applicablelowastWHO World Health Organization have not established risk-based drink-ing water criteria for Al Ag Be Bi Co Fe Mn Mo Si Sr Ti V and ZnlowastlowastCAA Codigo Alimentario ArgentinolowastlowastlowastProvisional guideline value
and mobility of As and F in groundwater [1] Kim et al [35]suggested that the cocontamination of As and F observed inoxidizing aquifers in many countries is associated with thedesorption from the Fe-(hydr) oxides by the pH increasesThe correlations between As and F are generally very high inthose aquifers because the As released from Fe-(hydr) oxidesdoes not readily precipitate again in the oxidizing alkalinecondition This is consistent with our observations as manyof the samples show high pH values and moderate coefficientcorrelation value between As and F (1199032 = 050) Alsosolubility of Al minerals may be enhanced by the complex ofdissolved Al with F that is also released from volcanic glasses
Vanadium in groundwater ranged between lt100 (QL)and 2646 120583g Lminus1 The highest V concentration was found insample M31 (Table 2) Vanadium shows a moderated positivecorrelation with As (1199032 = 042) and is likely to be derivedfrom similar mineral sources (secondary Fe and Mn oxides)under the high pH conditions [1] Our results also indicatethat Mo in general appears in low concentrations (Table 3)Molybdenum is weakly correlated with As (1199032 = 020)
Gomez et al [27] suggest that V U B and Mo areenriched in volcanic materials and are mobilized as vanadatemolybdate borate and so forth under oxidizing conditionsAlternatively they are mobilized in alkaline solutions under
conditions of high pH and high HCO3
minus controlled bycarbonate reactions (eg the F may be forming anioniccomplexes with B Fe and Al)
Antimony (Sb) is ubiquity a GroupV of the periodic tableand is similar to As in aspects as chemical behavior andtoxicity to animals [5] The Sb concentrations in studiedsamples exceeded 20120583g Lminus1 WHO and CAA drinking waterguideline values in 45 (245) of the analyzed samples(Tables 3 and 4)
Cadmium reaches a maximum of 70120583g Lminus1 with mostsamples being less than 30 120583g Lminus1 As this element formscationic species in solution its mobilization is not favoredunder the alkaline conditions of the groundwater [1]
The presence of arsenic and heavy metals in the samplescollected from this region of Chaco in Argentina may be dueto local geochemical conditions that facilitate the transfer ofnaturally occurring arsenic from soil and sediment to thewaterThe people in the Comandante FernandezDepartmentmay be overexposed not only toAs but also to B CdMn andF Adverse health effects may appear in coming years Thisproblem is a serious concern for the local population
4 Conclusions
The results of the current study indicate that approximately91 of the groundwater samples used for consumptionby human and livestock from the Comandante FernandezDepartment (Chaco province Argentina) exceed the WHOprovisional guideline value of 10 120583g Lminus1 As recommended asa maximum allowable level in potable water
Evaporation potentiated in arid and semiarid zonefavors the increase of salinity and alkalinity the results is alow quality of the resource but is not conditioning the con-centration of As and F Hence factors other than evaporationsuch as desorption from metal oxides and possibly silicatereaction could be likely controlling As and F mobiliza-tion Furthermore arsenic associated trace elements may beabsorbed on the surface of iron and aluminum oxides andoxyhydroxides (hematite goethite Fe(OH)
3
and gibbsite)limiting the mobility of trace elements Groundwater withhigh pH values and high concentration of bicarbonate wouldfacilitate the dissolution of volcanic glass thus trace elementsmay enter groundwater cycles forming anionic complexes inalkaline solutions and acquiring great mobility
The hydrochemical trace in the region is characterizedby high salinity and high As and F concentrations whichis related to volcanism and hydrothermal activity from theAndes This association is often linked to presence of BCd Mo Mn and V indicating their common origin in thevolcanic glasses
Due to high As concentrations found in groundwaterserious health risk must be considered The population inthe area may be exposed to the chronic toxicological effectsof hydro arsenicism and fluorosis increasing the risks ofcontracting other diseases derived from them Since thegroundwater studied here constitutes the principal source ofdrinking water in the zone mitigation efforts should not belimited to As health risks from other toxic elements presentin drinking water must also be addressed in this region
ISRN Environmental Chemistry 11
Conflict of Interest
The authors declare that there is no conflict of interestsregarding the publication of this paper Its publication isapproved by all authors and tacitly or explicitly by the respon-sible authorities where the work was carried out and that ifaccepted it will not be published elsewhere in the same formin English or in any other language including electronicallywithout the written consent of the copyright-holder
Acknowledgments
This work was supported with funds from PI 3600005 Uni-versidad Nacional del Chaco Austral (UNCAus) Patricia SBlanes thanks the National Academy of Exact Physic andNatural Sciences for granting a PhD fellowship
References
[1] P L Smedley H B Nicolli DM JMacdonald A J Barros andJ O Tullio ldquoHydrogeochemistry of arsenic and other inorganicconstituents in groundwaters from La Pampa ArgentinardquoApplied Geochemistry vol 17 no 3 pp 259ndash284 2002
[2] S Muhammad M T Shah and S Khan ldquoHealth risk assess-ment of heavy metals and their source apportionment in drink-ingwater of Kohistan region northern PakistanrdquoMicrochemicalJournal vol 98 no 2 pp 334ndash343 2011
[3] S S Farıas V A Casa C Vazquez L Ferpozzi G N Pucci andI M Cohen ldquoNatural contamination with arsenic and othertrace elements in ground waters of Argentine Pampean PlainrdquoScience of the Total Environment vol 309 no 1ndash3 pp 187ndash1992003
[4] L Jarup ldquoHazards of heavy metal contaminationrdquo British Med-ical Bulletin vol 68 pp 167ndash182 2003
[5] World Health Organization (WHO) ldquoRecommendationsrdquo inGuidelines for Drinking Water Quality vol 1 Geneva Switzer-land 4th edition 2011
[6] C Hopenhayn ldquoArsenic in drinking water impact on humanhealthrdquo Elements vol 2 no 2 pp 103ndash107 2006
[7] S H Lamm and M B Kruse ldquoArsenic ingestion and bladdercancermortalitymdashwhat do the dose-response relationships sug-gest aboutmechanismrdquoHumanandEcological RiskAssessmentvol 11 no 2 pp 433ndash450 2005
[8] C-HWang C K Hsiao C-L Chen et al ldquoA review of the epi-demiologic literature on the role of environmental arsenicexposure and cardiovascular diseasesrdquo Toxicology and AppliedPharmacology vol 222 no 3 pp 315ndash326 2007
[9] J Bundschuh M I Litter F Parvez et al ldquoOne century ofarsenic exposure in Latin America a review of history andoccurrence from 14 countriesrdquo Science of the Total Environmentvol 429 pp 2ndash35 2012
[10] M T Alarcon-Herrera J Bundschuh B Nath et al ldquoCo-occurrence of arsenic and fluoride in groundwater of semi-aridregions in Latin America genesis mobility and remediationrdquoJournal of Hazardous Materials 2012
[11] E E Buchhamer P S Blanes RM Osicka andM C GimenezldquoEnvironmental risk assessment of arsenic and fluoride in thechaco province argentina research advancesrdquo Journal of Toxi-cology and Environmental Health A vol 75 no 22-23 pp 1437ndash1450 2012
[12] A Cabrera M Blarasin E Matteoda G Villalva and M LGomez ldquoComposicion quımica del agua subterranea en el surde Cordoba lınea de base hidroquımica o fondo natural enreferencia a arsenico y fluorrdquo in Aguas Superficiales y Sub-terraneas en el sur ae Cordoba Una Perspectiva GeoambientalM Blarasin S Degiovanni A Cabera and M Villegas Edspp 81ndash90 Universidad Nacional de Rıo Cuarto Rıo CuartoArgentina 2005
[13] P Bhattacharya M Claesson J Bundschuh et al ldquoDistributionand mobility of arsenic in the Rıo Dulce alluvial aquifers inSantiago del Estero Province Argentinardquo Science of the TotalEnvironment vol 358 no 1ndash3 pp 97ndash120 2006
[14] B Nicolli O C Tujchneider M C Paris M Blanco and A JBarros ldquoMovilidad del arsenico y oligoelementos asociados enaguas subterraneas del centro-norte de la provincia de Santa FeArgentinardquo in Proceedings of the Presencia de Fluor y Arsenicoen Aguas Subterraneas VI Congreso Hidrogeologico ArgentinoG Galindo J L Fernandez Turiel and A Storniolo Eds pp81ndash90 Santa Rosa La Pampa Argentina 2009
[15] H B Nicolli A Tineo J W Garcıa C M Falcon and PL Smedley ldquoMobilization of arsenic and other trace elementof health concern in groundwater from the Salı River BasinTucuman Province Argentinardquo Environmental Geochemistryand Health vol 34 no 2 pp 251ndash262 2012
[16] RMOsicka N Agullo C Herrera Ahuad andMC GimenezldquoEvaluacion de las concentraciones de fluoruro y arsenico enlas aguas subterraneas del Domo Central de la provincia delChacordquo Comunicaciones Cientıficas y Tecnologicas Univer-sidad Nacional del Nordeste 2002 httpwwwunneeduarunneviejaWebcytcyt200208-ExactasE-049pdf
[17] C E Fiorentino J D Paoloni M E Sequeira and P ArosteguyldquoThe presence of vanadium in groundwater of southeasternextreme the pampean region Argentina Relationship withother chemical elementsrdquo Journal of Contaminant Hydrologyvol 93 no 1ndash4 pp 122ndash129 2007
[18] P Sprechmann F G Acenaloza C Gaucher A C R Nogueiraand M J Perez ldquoTrasgresion Paranaense paleoestuario deltethys del miocenomedio yo superior en Sudamericardquo in Con-greso Latinoamericano de Geologıa Montevideo-UruguayAbstracts 1 CDRoom pp 10ndash15 Sociedad Latinoamericana deGeologıa 2001
[19] F Larroza and L S Farina ldquoCaracterizacion hidrogeologica delsistema acuıfero Yrenda (SAY) en Paraguay recurso compar-tido con y Boliviardquo in Proceedings of the IV Congreso Argentinode Hidrogeologıa TOMO II Argentinarıo Cuarto CordobaArgentina 2005
[20] E Popolizio P Y Serra and G O Hort ldquoLa clasificaciontaxonomica del Chacordquo Centro de Geociencia Aplicada vol 3no 1 pp 11ndash32 1980
[21] INTA ldquoInstituto Nacional de Tecnologıa AgropecuariardquoAgrometeorologıa httpwwwintagovarsaenzpemeteorolo-giameteorologiahtm
[22] M G Garcıa O Sracek D S Fernandez andM D V HidalgoldquoFactors affecting arsenic concentration in groundwaters fromNorthwestern Chaco-Pampean Plain Argentinardquo Environmen-tal Geology vol 52 no 7 pp 1261ndash1275 2007
[23] US Environmental Protection Agency ( EPA) ldquoArsenic Inor-ganic United States Environmental Protection Agency Inte-grated Risk Information System (IRIS) (CASRN 7440-38-2)rdquo1998 httpwwwepagovirissubst0278htm
12 ISRN Environmental Chemistry
[24] Comision Nacional de Alimentos (CONAL) Acta Nž 93Reunion Ordinaria 3011 y 0112-2011 (Prorroga Art 982 y 983del CAA)
[25] CAA (Codigo Alimentario Argentino) Cap XII Bebidashıdricas agua y agua gasificada In Codigo Alimentario Argen-tino modificatoria del Art 982 (Res 682007 y 1962007) Ley18 284 Buenos Aires Argentina 2007 httpwwwanmatgovarCODIGOACapitulo XII Agua 2007-05pdf
[26] J L Fernandez Turiel G GalindoM A Parada D GimenoMGarcıa-Valles and J Saavedra ldquoEstado actual del conocimientosobre el arsenico en el agua de Argentina y Chile origenmovilidad y transporterdquo inArsenico en Agua Origen movilidady tratamiento II Seminario Hispano-Latinoamericano sobreTemas Actuales de Hidrologıa Subterranea y IV Congreso Hidro-geologico Argentino pp 1ndash22 Rıo Cuarto Argentina 2005
[27] M L Gomez M T Blarasin and D E Martınez ldquoArsenic andfluoride in a loess aquifer in the central area of Argentinardquo Envi-ronmental Geology vol 57 no 1 pp 143ndash155 2009
[28] P L Smedley D G Kinniburgh D M J Macdonald et alldquoArsenic associations in sediments from the loess aquifer of LaPampa Argentinardquo Applied Geochemistry vol 20 no 5 pp989ndash1016 2005
[29] D L Ozsvath ldquoFluoride and environmental health a reviewrdquoReviews in Environmental Science and Biotechnology vol 8 no1 pp 59ndash79 2009
[30] E M Farfan Torres P M Naranjo A Boemo I Lomnicziand L Lorenzo ldquoDistribution of arsenic in groundwater in theChaco Salteno Argentinardquo in Workshop on as Distribution inIbero-America M I Litter Ed CyTED IBEROARSENAbstractBook pp 57ndash60 2006
[31] httpwwwjctoniccomincludemineralsboronhtm[32] M A Halim R K Majumder S A Nessa et al ldquoEvaluation
of processes controlling the geochemical constituents in deepgroundwater in Bangladesh spatial variability on arsenic andboron enrichmentrdquo Journal of HazardousMaterials vol 180 no1ndash3 pp 50ndash62 2010
[33] J BuschmannM Berg C Stengel andM L Sampson ldquoArsenicand manganese contamination of drinking water resources inCambodia coincidence of risk areaswith low relief topographyrdquoEnvironmental Science and Technology vol 41 no 7 pp 2146ndash2152 2007
[34] R A Beckman A S Mildvan and L A Loeb ldquoOn the fidelityof DNA replication manganese mutagenesis in vitrordquo Biochem-istry vol 24 no 21 pp 5810ndash5817 1985
[35] S-H Kim K Kim K-S Ko Y Kim and K-S Lee ldquoCo-con-tamination of arsenic andfluoride in the groundwater of uncon-solidated aquifers under reducing environmentsrdquoChemospherevol 87 no 8 pp 851ndash856 2012
M44 11 707 250 723 450 901 561 223 303 132 646 CandashClM45 12 681 144 298 5674 263 424 459 286 1100 400 CandashClNd non detected All concentrations are expressed as mg Lminus1
ISRN Environmental Chemistry 5
Diagrama Piper
20
20
20
40
40
40
60
60
60
80
80
80
20
20
20
40
40
40
60
60
60
80
80
80
20
8080
20
40
6060
40
60
4040
60
80
2020
80
Mg (
)
Ca () Cl ()
Na + K ()
Na + K ()
SO4
+ Cl (
) Ca + Mg ()
HCO3
+ CO
3
SO4 ()
HCO3
+ CO
3(
)
Figure 2 Piper diagram showing the chemical compositions of groundwater samples
(1199032 = 091 1199032 = 069) and sulfate versus EC and sodium(1199032 = 062 1199032 = 061) which is related to the predominanceof sodium chloride types in groundwater with higher salinitySodium bicarbonate waters are related generally with lowsalinity samples in analyzed groundwater samples the ECshows poor correlation with HCO
3
minus (1199032 = 021)Results of chemical analysis show large variations in
chemical composition and also indicate the high salinity ofmany of the groundwater samples According to Larroza andFarina [19] the salinity of groundwater in the basin of theChaco region is due to the previous existence of a shallowsea of restricted environment which has left its salts thisgeographical feature called Paranaense Sea has originatedduring the Middle and Upper Miocene The extremelyheterogeneous values of EC from groundwater could beexplained by the local variation in sedimentary and hydro-geological characteristics [13] Moreover the evaporation inarid and semiarid zones favors the increase of salinity andalkalinity [15 22]
32 Total Arsenic and Fluoride Arsenic is classified as ahuman carcinogen (Type A) based on sufficient epidemio-logic evidence linking increased mortality from liver kidneybladder and lung cancers to drinking As-contaminatedwater[23] The provisional guideline value recommended by theWHO [5] for this carcinogenic contaminant in drinkingwater is 10 120583g Lminus1 and in Argentina this would be enforcedin 2017 [24] On the basis of this criterion only 9 (445)of groundwater source is within levels recommended forconsumption whereas about 73 (3345) of all analyzedsamples showed As values above 50 120583g Lminus1 (CAA) [25]Mean concentration of total arsenic in groundwater was213 120583g Lminus1 and maximum was 1990120583g Lminus1 (Table 2) Thehighest As concentrationwas found in groundwater collectedin sample M36 The presence of arsenic in the groundwatersamples collected from this region of Argentina is naturalthe local geology and rainfall have been shown to havemajor impact on the variations of As concentration ingroundwater
6 ISRN Environmental Chemistry
Table 2 Statistical summary of the chemistry of groundwater (major ions and trace elements 119899 = 45) from Comandante Fernandez Depart-ment Chaco Northeast Argentina
Parameter Mean Median Range 10th percentil 90th percentil Standard deviationDepth (m) 220 130 500ndash220 800 500 331pH 754 751 650ndash894 690 822 055EC (mScm) 527 250 069ndash249 099 134 628HCO
Different positive correlation were observed in ground-water between As versus HCO
3
minus and Na+ (1199032 = 075 1199032 =045) and a negative correlation was found between As andCa2+ (1199032 = minus005) It could be assumed that As is associatedwith NandashHCO
3
minus system related to feldspar dissolution [26]Based on values of pH found in groundwater of this region ofChaco including data reported from other sites of the region[1 13 27] it can be presumed that pH controls As mobility
The study made by Smedley et al [28] reveals that highlyAs(V)-contaminated groundwater in oxidizing environmentsthroughout the world are characterized by high concen-tration of HCO
3
minus (gt500mg Lminus1) and SO4
2minus (gt250mg Lminus1)and pH gt 750 Similar geochemical conditions occur in theChaco-Pampean plain like in the arid regions of Santiagodel Estero Cordoba y La Pampa [13 14 27] High As con-centrations are common and dominated by As(V) and thegroundwater have correspondingly high F concentrationsThese general characteristic are consistent with the analyzed
groundwater However arsenic speciation is not performedin the present study
On the other hand smaller quantities of fluoride ion inthe order of 1mg Lminus1 in ingested water are usually consideredto have a beneficial effect by lowering the rate of occurrenceof dental caries Excessive intake (gt15mg Lminus1) would resultsin pathological changes in teeth and bones such as mottlingof teeth or dental fluorosis along with metabolic changesreported on soft tissues such as thyroid reproductive organsbrain liver and kidneys [29]
TheWHOguideline value for F concentration in drinkingwater is 15mg Lminus1 [5] whereas the Codigo AlimentarioArgentino (CCA) [25] establishes a limit that varies accordingto the average temperature of the place (1mg Lminus1 for an aver-age temperature of 215∘C in the area under study) Thedistribution of F concentrations is heterogeneous and similarto As A positive correlation was observed between As andF with 1199032 = 050 The analyzed groundwater 31 (1445) of
ISRN Environmental Chemistry 7
the samples exceeded theWHO guideline value of 15mg Lminus1[5] About 47 of all analyzed samples showed F values above1mg Lminus1 recommended by CAA (Table 4) Similar correla-tions between As and F were also observed in groundwaterfrom neighboring Santiago del Estero [13] Santa Fe [14] andSalta Provinces [30]
In the same way as arsenic the F rich water is character-ized by high concentration of Na+ and low concentration ofCa2+ and Mg2+ (1199032 = 045 009 and 016 resp) Fluoride is ahighly reactive element that combines with other elements incovalent and ionic bonds It is mainly found in alkaline rocksand alkaline soils fluorite being the principal componentGomez et al [27] explain that the processes that could controlthe low relationship between F and Ca2+ and the positiverelationship between F and bicarbonate (1199032 = 024) would bethe balance equation relating calcite and fluorite when bothare in contact with water
As and other trace elements such as V Mo U and minorelements such as B and F are presumed to have their originalsource in volcanic ashes originated from the volcanismin the Andes (5ndash25 in the loess-type sediments of theChaco-Pampean plain) [9] The main components of thesesediments are feldspars quartz volcanic glass shards andminor amounts of muscovite and calcite The compositionof volcanic glass is typically rhyolitic containing a highconcentration of F As V and B among other trace elements[28]
33 Other Trace Elements A series of various trace elementsincluding Ag Al B Ba Be Cd Co Cr Cu Fe Mn MoNi P Pb S Sb Se Si Sr Ti V and Zn were also deter-mined in the studied groundwater The concentrations oftarget elements are summarized in Table 3 Among all 23target analytes concentrations exceeding the WHO recom-mended drinking water limits (in parentheses) were foundfor B (2400120583g Lminus1) Ba (700 120583g Lminus1) Cd (3 120583g Lminus1) and Sb(20120583g Lminus1) Table 4 shows the percentage of groundwatersamples exceeding these WHO and CAA elemental concen-tration guidelines On the other hand concentrations of SnCo Cu Ni S Se Sr V and Zn were very low Silver beryl-lium chrome selenium lead and titanium are not includ inTables 2 and 3 because these elements were never found aboverespective quantification limits
From the samples investigated only one (M45) showedelevated value of barium (1400 120583g Lminus1) than in the WHOdrinking water guideline (700 120583g Lminus1) with an average valueof 122120583g Lminus1 (Table 2)
In small quantities B is essential for healthy bones jointfunction and the metabolism of steroidal hormonesBoron deficiency seems to affect calcium and magnesiummetabolism and affects the composition structure andstrength of bone [31]The concentrations of boron (B) rangedfrom 1560 to 21910 120583g Lminus1 with an average of 4020120583g Lminus1(Table 2) Boron concentration in the 44 (2045) ofthe samples exceeds the WHO and 78 (3545) of thesamples exceeds the CAA standard limits for drinking water(Table 4) The highest concentration of boron was observedin sample M40 which is associated with the largest value
of EC (19371 120583S cmminus1) In general the presence of boron ingroundwater depends on its salinity (represented as EC) suchthat it increases with increasing salinity [32] In this studya positive correlation between EC and boron (1199032 = 064)suggests that boron might be associated with the salinity ofthese samplesHence the salinitymainly reflects the variationof Clminus concentration with a strong linear correlation(1199032 = 091) between EC and Clminus suggesting that the increaseof Clminus concentration contributes to increase in EC valueThehydraulic conductivity salinity type of clay sediments pHand temperature are the crucial factors that determine boronmobility in the groundwater system [32] Boron was stronglycorrelated with Na+ K+ Mg2+ Clminus SO
4
2minus HCO3
minus andAs probably due to their common origin The correlationbetween B and As is often observed in groundwater [1 13]
Our results indicate that approximately 31 of thegroundwater samples tested exceeded the CAA criteria of300 120583g Lminus1 for total Fe in drinking water The highest totalFe concentration (2000120583g Lminus1) appeared in sample M38 Ingeneral Fe concentrationwas low in the studied groundwatersamples only fourteen samples had higher Fe with a meanvalue of 276120583g Lminus1 and median value of 81 120583g Lminus1 On theother hand weaker correlation is observed between Fe andAsin groundwater (1199032 = 017) Moreover almost all groundwa-ter with high Fe concentration (gt300120583g Lminus1) contained totalAs concentration over 10 120583g Lminus1 (Table 3)
The concentration of dissolved Al varied between 600to 17380 120583g Lminus1 with a mean value of 561120583g Lminus1 (Table 2)A 16 (745) exceeded the 200120583g Lminus1 CAA drinking waterguideline However the mean concentration of Al decreasessignificantly down to 178120583g Lminus1 (median 985120583g Lminus1) if theanomalous of sample M24 is excluded Also Aluminumshows no correlation with As (1199032 = minus006)
Manganese exceeded the 100 120583g Lminus1 CAA drinking waterguideline value in 13 (645) of the samples (Tables 3 and4) The highest Mn concentration (3740 120583g Lminus1) was foundin sample M32 However the mean concentration of Mndecreases significantly from 152 to 700 120583g Lminus1 (median500120583g Lminus1) if the anomalous value of this sample is exclud-ed Manganese shows no correlation with As (1199032 = minus007)Mn is known as an essential element for human survivalserves as a catalyst and cofactor in many enzymatic processesinvolved in the synthesis of fatty acids and cholesterol Thechronic ingestion of Mn in drinking water is associated withneurologic damage [33] Moreover manganese is a knownmutagen [34]
Many samples have Fe Al and Mn concentrationsbelow detection limits and most have below CAA guidelinevalue However concentrations are higher in a few samples(Table 2) Smedley et al [1] suggest that at the pH of thegroundwater the high concentrations for these elements traceare most likely due to presence of colloidal particles As thegroundwater are oxidizing solubility of Fe Al andMnoxidesis low and concentrations of dissolved Fe Al and Mn aretherefore mostly low
The processes of dissolution and release from oxides andoxyhydroxides mainly Al Mn and Fe control the presence
8 ISRN Environmental Chemistry
Table3Tracee
lementcom
positionof
grou
ndwater
samples
from
theC
omandanteF
ernand
ezDepartm
entCh
aco
SampleID
As(to
t)F
Al
FeMn
BBa
Mo
SiV
Cd
SrCo
Ni
ZnCu
SP (
tot)
SbQL
500
010
100
100
500
200
100
100
500
100
300
250
100
100
100
100
0025
010
250
M1
500
190
110
600
500
1598
bql
126
bql
830
500
730
bql
bql
bql
bql
110
080
bql
M2
250
050
120
401
bql
310
156
bql
309
450
bql
420
bql
bql
bql
bql
200
030
bql
M3
100
180
900
160
300
875
bql
bql
bql
100
bql
691
bql
bql
300
bql
107
290
bql
M4
150
030
100
bql
bql
206
bql
bql
bql
220
bql
290
bql
bql
bql
bql
700
030
bql
M5
127
074
220
bql
900
811
791
420
227
119bq
l594
bql
bql
410
bql
020
090
bql
M6
580
080
110
bql
bql
297
100
bql
bql
440
bql
498
bql
bql
bql
bql
700
050
bql
M7
240
040
100
bql
bql
275
482
120
bql
430
bql
230
bql
bql
bql
bql
800
030
bql
M8
120
100
100
bql
600
2654
790
bql
2099
900
300
2012
bql
bql
bql
bql
110
080
bql
M9
178
198
130
550
700
1550
101
990
549
163
700
811
bql
bql
bql
630
700
080
900
M10
500
260
800
220
870
15070
bql
160
16570
390
400
4871
bql
bql
bql
bql
725
190
bql
M11
250
224
100
bql
600
1387
bql
140
480
230
bql
641
bql
bql
bql
bql
132
050
bql
M12
110
044
100
bql
194
500
620
bql
114530
bql
334
bql
100
bql
bql
130
060
bql
M13
952
110
110
bql
500
500
269
420
bql
760
400
683
bql
bql
bql
bql
100
030
300
M14
11615
0110
bql
500
665
bql
431
bql
650
500
540
bql
bql
bql
bql
700
070
bql
M15
310
050
102
500
500
2449
402
303
680
570
bql
521
bql
bql
bql
bql
490
060
bql
M16
290
040
130
150
500
255
518
bql
490
110
bql
362
bql
bql
bql
bql
260
030
bql
M17
830
120
100
bql
bql
1782
403
bql
3940
940
300
1427
bql
bql
bql
bql
113
020
300
M18
620
080
700
bql
182
734
bql
bql
2550
280
bql
2510
bql
bql
bql
bql
281
060
bql
M19
100
020
110
bql
500
298
144
bql
bql
300
bql
157
bql
bql
bql
bql
800
050
bql
M20
112
145
100
bql
bql
2316
220
109
4750
112
300
1390
bql
bql
bql
bdl
147
040
bql
M21
700
190
100
bql
254
2470
bql
112
353
280
bql
1361
bql
bql
bql
bql
415
890
bql
M22
100
020
100
bql
292
156
169
bql
bql
bql
bql
860
bql
bql
bql
bql
600
150
bql
M23
360
030
110
bql
bql
630
109
bql
bql
300
bql
225
bql
bql
bql
bql
500
070
900
M24
860
075
17380
310
296
21560
111
bql
1380
120
300
324
bql
bql
321
bql
010
080
bql
M25
770
120
2980
bql
521
6308
bql
bql
1647
220
Bql
bql
bql
100
2831
320
010
250
400
M26
100
340
600
110
bql
1800
150
210
150
198
300
150
bql
bql
bql
bql
006
180
bql
M27
214
420
600
855
bql
6890
bql
213
150
560
300
213
280
bql
670
280
006
110
bql
M28
100
340
600
428
bql
8450
bql
214
150
219
300
150
220
bql
bql
220
006
670
bql
M29
100
060
600
660
bql
6850
bql
208
150
100
300
150
bql
bql
670
bql
006
770
bql
M30
244
090
600
810
330
3050
185
210
150
547
300
150
bql
bql
240
bql
006
130
250
M31
770
340
280
1013
230
7290
bql
210
150
2646
300
322
bql
bql
bql
bql
030
030
bql
M32
700
010
210
286
3740
5080
632
209
150
bql
300
164
640
bql
110
640
020
230
300
M33
174
170
600
734
321
2790
690
210
7540
266
300
150
bql
bql
270
bql
Bql
220
bql
M34
317
030
360
575
240
1970
118
214
150
436
300
150
bql
bql
bql
bql
040
060
bql
M35
1073
030
600
194
bql
6340
301
205
150
1249
300
150
120
bql
490
120
006
030
300
M36
1990
425
600
510
135580
bql
210
150
251
300
288
240
bql
130
bql
006
530
300
M37
200
030
570
606
131290
113
210
150
387
300
203
240
100
160
670
060
050
bql
M38
150
190
600
2000
bql
3710
bql
210
150
380
300
200
950
bql
bql
bql
006
030
300
M39
200
050
600
300
bql
4830
140
210
150
104
300
200
bql
bql
bql
670
006
990
140
ISRN Environmental Chemistry 9
Table3Con
tinued
SampleID
As(to
t)F
Al
FeMn
BBa
Mo
SiV
Cd
SrCo
Ni
ZnCu
SP (
tot)
SbM40
200
050
600
689
bql
21910
bql
210
150
124
300
200
bql
bql
bql
240
006
130
300
M41
150
150
600
988
bql
21580
bql
210
150
176
300
302
bql
bql
bql
bql
006
110
300
M42
130
080
600
426
bql
1970
bql
210
150
345
300
369
180
bql
270
111
006
020
300
M43
150
140
600
700
431
1030
107
210
150
bql
300
bql
550
bql
220
270
006
080
bql
M44
100
120
600
800
bql
2600
289
210
150
191
300
bql
bql
bql
bql
bql
006
480
bql
M45
200
160
600
262
331
240
1400
210
150
350
300
bql
bql
bql
110490
006
230
bql
QLqu
antifi
ctionlim
itbq
lbello
wqu
antifi
catio
nlim
itallcon
centratio
nsaree
xpressed
as120583gLminus1excepted
forF
Sand
Pexpressedas
mgLminus1
10 ISRN Environmental Chemistry
Table 4 Risk-based drinking water criteria and the percentage ofgroundwater samples exceeding these criteria
NA not applicablelowastWHO World Health Organization have not established risk-based drink-ing water criteria for Al Ag Be Bi Co Fe Mn Mo Si Sr Ti V and ZnlowastlowastCAA Codigo Alimentario ArgentinolowastlowastlowastProvisional guideline value
and mobility of As and F in groundwater [1] Kim et al [35]suggested that the cocontamination of As and F observed inoxidizing aquifers in many countries is associated with thedesorption from the Fe-(hydr) oxides by the pH increasesThe correlations between As and F are generally very high inthose aquifers because the As released from Fe-(hydr) oxidesdoes not readily precipitate again in the oxidizing alkalinecondition This is consistent with our observations as manyof the samples show high pH values and moderate coefficientcorrelation value between As and F (1199032 = 050) Alsosolubility of Al minerals may be enhanced by the complex ofdissolved Al with F that is also released from volcanic glasses
Vanadium in groundwater ranged between lt100 (QL)and 2646 120583g Lminus1 The highest V concentration was found insample M31 (Table 2) Vanadium shows a moderated positivecorrelation with As (1199032 = 042) and is likely to be derivedfrom similar mineral sources (secondary Fe and Mn oxides)under the high pH conditions [1] Our results also indicatethat Mo in general appears in low concentrations (Table 3)Molybdenum is weakly correlated with As (1199032 = 020)
Gomez et al [27] suggest that V U B and Mo areenriched in volcanic materials and are mobilized as vanadatemolybdate borate and so forth under oxidizing conditionsAlternatively they are mobilized in alkaline solutions under
conditions of high pH and high HCO3
minus controlled bycarbonate reactions (eg the F may be forming anioniccomplexes with B Fe and Al)
Antimony (Sb) is ubiquity a GroupV of the periodic tableand is similar to As in aspects as chemical behavior andtoxicity to animals [5] The Sb concentrations in studiedsamples exceeded 20120583g Lminus1 WHO and CAA drinking waterguideline values in 45 (245) of the analyzed samples(Tables 3 and 4)
Cadmium reaches a maximum of 70120583g Lminus1 with mostsamples being less than 30 120583g Lminus1 As this element formscationic species in solution its mobilization is not favoredunder the alkaline conditions of the groundwater [1]
The presence of arsenic and heavy metals in the samplescollected from this region of Chaco in Argentina may be dueto local geochemical conditions that facilitate the transfer ofnaturally occurring arsenic from soil and sediment to thewaterThe people in the Comandante FernandezDepartmentmay be overexposed not only toAs but also to B CdMn andF Adverse health effects may appear in coming years Thisproblem is a serious concern for the local population
4 Conclusions
The results of the current study indicate that approximately91 of the groundwater samples used for consumptionby human and livestock from the Comandante FernandezDepartment (Chaco province Argentina) exceed the WHOprovisional guideline value of 10 120583g Lminus1 As recommended asa maximum allowable level in potable water
Evaporation potentiated in arid and semiarid zonefavors the increase of salinity and alkalinity the results is alow quality of the resource but is not conditioning the con-centration of As and F Hence factors other than evaporationsuch as desorption from metal oxides and possibly silicatereaction could be likely controlling As and F mobiliza-tion Furthermore arsenic associated trace elements may beabsorbed on the surface of iron and aluminum oxides andoxyhydroxides (hematite goethite Fe(OH)
3
and gibbsite)limiting the mobility of trace elements Groundwater withhigh pH values and high concentration of bicarbonate wouldfacilitate the dissolution of volcanic glass thus trace elementsmay enter groundwater cycles forming anionic complexes inalkaline solutions and acquiring great mobility
The hydrochemical trace in the region is characterizedby high salinity and high As and F concentrations whichis related to volcanism and hydrothermal activity from theAndes This association is often linked to presence of BCd Mo Mn and V indicating their common origin in thevolcanic glasses
Due to high As concentrations found in groundwaterserious health risk must be considered The population inthe area may be exposed to the chronic toxicological effectsof hydro arsenicism and fluorosis increasing the risks ofcontracting other diseases derived from them Since thegroundwater studied here constitutes the principal source ofdrinking water in the zone mitigation efforts should not belimited to As health risks from other toxic elements presentin drinking water must also be addressed in this region
ISRN Environmental Chemistry 11
Conflict of Interest
The authors declare that there is no conflict of interestsregarding the publication of this paper Its publication isapproved by all authors and tacitly or explicitly by the respon-sible authorities where the work was carried out and that ifaccepted it will not be published elsewhere in the same formin English or in any other language including electronicallywithout the written consent of the copyright-holder
Acknowledgments
This work was supported with funds from PI 3600005 Uni-versidad Nacional del Chaco Austral (UNCAus) Patricia SBlanes thanks the National Academy of Exact Physic andNatural Sciences for granting a PhD fellowship
References
[1] P L Smedley H B Nicolli DM JMacdonald A J Barros andJ O Tullio ldquoHydrogeochemistry of arsenic and other inorganicconstituents in groundwaters from La Pampa ArgentinardquoApplied Geochemistry vol 17 no 3 pp 259ndash284 2002
[2] S Muhammad M T Shah and S Khan ldquoHealth risk assess-ment of heavy metals and their source apportionment in drink-ingwater of Kohistan region northern PakistanrdquoMicrochemicalJournal vol 98 no 2 pp 334ndash343 2011
[3] S S Farıas V A Casa C Vazquez L Ferpozzi G N Pucci andI M Cohen ldquoNatural contamination with arsenic and othertrace elements in ground waters of Argentine Pampean PlainrdquoScience of the Total Environment vol 309 no 1ndash3 pp 187ndash1992003
[4] L Jarup ldquoHazards of heavy metal contaminationrdquo British Med-ical Bulletin vol 68 pp 167ndash182 2003
[5] World Health Organization (WHO) ldquoRecommendationsrdquo inGuidelines for Drinking Water Quality vol 1 Geneva Switzer-land 4th edition 2011
[6] C Hopenhayn ldquoArsenic in drinking water impact on humanhealthrdquo Elements vol 2 no 2 pp 103ndash107 2006
[7] S H Lamm and M B Kruse ldquoArsenic ingestion and bladdercancermortalitymdashwhat do the dose-response relationships sug-gest aboutmechanismrdquoHumanandEcological RiskAssessmentvol 11 no 2 pp 433ndash450 2005
[8] C-HWang C K Hsiao C-L Chen et al ldquoA review of the epi-demiologic literature on the role of environmental arsenicexposure and cardiovascular diseasesrdquo Toxicology and AppliedPharmacology vol 222 no 3 pp 315ndash326 2007
[9] J Bundschuh M I Litter F Parvez et al ldquoOne century ofarsenic exposure in Latin America a review of history andoccurrence from 14 countriesrdquo Science of the Total Environmentvol 429 pp 2ndash35 2012
[10] M T Alarcon-Herrera J Bundschuh B Nath et al ldquoCo-occurrence of arsenic and fluoride in groundwater of semi-aridregions in Latin America genesis mobility and remediationrdquoJournal of Hazardous Materials 2012
[11] E E Buchhamer P S Blanes RM Osicka andM C GimenezldquoEnvironmental risk assessment of arsenic and fluoride in thechaco province argentina research advancesrdquo Journal of Toxi-cology and Environmental Health A vol 75 no 22-23 pp 1437ndash1450 2012
[12] A Cabrera M Blarasin E Matteoda G Villalva and M LGomez ldquoComposicion quımica del agua subterranea en el surde Cordoba lınea de base hidroquımica o fondo natural enreferencia a arsenico y fluorrdquo in Aguas Superficiales y Sub-terraneas en el sur ae Cordoba Una Perspectiva GeoambientalM Blarasin S Degiovanni A Cabera and M Villegas Edspp 81ndash90 Universidad Nacional de Rıo Cuarto Rıo CuartoArgentina 2005
[13] P Bhattacharya M Claesson J Bundschuh et al ldquoDistributionand mobility of arsenic in the Rıo Dulce alluvial aquifers inSantiago del Estero Province Argentinardquo Science of the TotalEnvironment vol 358 no 1ndash3 pp 97ndash120 2006
[14] B Nicolli O C Tujchneider M C Paris M Blanco and A JBarros ldquoMovilidad del arsenico y oligoelementos asociados enaguas subterraneas del centro-norte de la provincia de Santa FeArgentinardquo in Proceedings of the Presencia de Fluor y Arsenicoen Aguas Subterraneas VI Congreso Hidrogeologico ArgentinoG Galindo J L Fernandez Turiel and A Storniolo Eds pp81ndash90 Santa Rosa La Pampa Argentina 2009
[15] H B Nicolli A Tineo J W Garcıa C M Falcon and PL Smedley ldquoMobilization of arsenic and other trace elementof health concern in groundwater from the Salı River BasinTucuman Province Argentinardquo Environmental Geochemistryand Health vol 34 no 2 pp 251ndash262 2012
[16] RMOsicka N Agullo C Herrera Ahuad andMC GimenezldquoEvaluacion de las concentraciones de fluoruro y arsenico enlas aguas subterraneas del Domo Central de la provincia delChacordquo Comunicaciones Cientıficas y Tecnologicas Univer-sidad Nacional del Nordeste 2002 httpwwwunneeduarunneviejaWebcytcyt200208-ExactasE-049pdf
[17] C E Fiorentino J D Paoloni M E Sequeira and P ArosteguyldquoThe presence of vanadium in groundwater of southeasternextreme the pampean region Argentina Relationship withother chemical elementsrdquo Journal of Contaminant Hydrologyvol 93 no 1ndash4 pp 122ndash129 2007
[18] P Sprechmann F G Acenaloza C Gaucher A C R Nogueiraand M J Perez ldquoTrasgresion Paranaense paleoestuario deltethys del miocenomedio yo superior en Sudamericardquo in Con-greso Latinoamericano de Geologıa Montevideo-UruguayAbstracts 1 CDRoom pp 10ndash15 Sociedad Latinoamericana deGeologıa 2001
[19] F Larroza and L S Farina ldquoCaracterizacion hidrogeologica delsistema acuıfero Yrenda (SAY) en Paraguay recurso compar-tido con y Boliviardquo in Proceedings of the IV Congreso Argentinode Hidrogeologıa TOMO II Argentinarıo Cuarto CordobaArgentina 2005
[20] E Popolizio P Y Serra and G O Hort ldquoLa clasificaciontaxonomica del Chacordquo Centro de Geociencia Aplicada vol 3no 1 pp 11ndash32 1980
[21] INTA ldquoInstituto Nacional de Tecnologıa AgropecuariardquoAgrometeorologıa httpwwwintagovarsaenzpemeteorolo-giameteorologiahtm
[22] M G Garcıa O Sracek D S Fernandez andM D V HidalgoldquoFactors affecting arsenic concentration in groundwaters fromNorthwestern Chaco-Pampean Plain Argentinardquo Environmen-tal Geology vol 52 no 7 pp 1261ndash1275 2007
[23] US Environmental Protection Agency ( EPA) ldquoArsenic Inor-ganic United States Environmental Protection Agency Inte-grated Risk Information System (IRIS) (CASRN 7440-38-2)rdquo1998 httpwwwepagovirissubst0278htm
12 ISRN Environmental Chemistry
[24] Comision Nacional de Alimentos (CONAL) Acta Nž 93Reunion Ordinaria 3011 y 0112-2011 (Prorroga Art 982 y 983del CAA)
[25] CAA (Codigo Alimentario Argentino) Cap XII Bebidashıdricas agua y agua gasificada In Codigo Alimentario Argen-tino modificatoria del Art 982 (Res 682007 y 1962007) Ley18 284 Buenos Aires Argentina 2007 httpwwwanmatgovarCODIGOACapitulo XII Agua 2007-05pdf
[26] J L Fernandez Turiel G GalindoM A Parada D GimenoMGarcıa-Valles and J Saavedra ldquoEstado actual del conocimientosobre el arsenico en el agua de Argentina y Chile origenmovilidad y transporterdquo inArsenico en Agua Origen movilidady tratamiento II Seminario Hispano-Latinoamericano sobreTemas Actuales de Hidrologıa Subterranea y IV Congreso Hidro-geologico Argentino pp 1ndash22 Rıo Cuarto Argentina 2005
[27] M L Gomez M T Blarasin and D E Martınez ldquoArsenic andfluoride in a loess aquifer in the central area of Argentinardquo Envi-ronmental Geology vol 57 no 1 pp 143ndash155 2009
[28] P L Smedley D G Kinniburgh D M J Macdonald et alldquoArsenic associations in sediments from the loess aquifer of LaPampa Argentinardquo Applied Geochemistry vol 20 no 5 pp989ndash1016 2005
[29] D L Ozsvath ldquoFluoride and environmental health a reviewrdquoReviews in Environmental Science and Biotechnology vol 8 no1 pp 59ndash79 2009
[30] E M Farfan Torres P M Naranjo A Boemo I Lomnicziand L Lorenzo ldquoDistribution of arsenic in groundwater in theChaco Salteno Argentinardquo in Workshop on as Distribution inIbero-America M I Litter Ed CyTED IBEROARSENAbstractBook pp 57ndash60 2006
[31] httpwwwjctoniccomincludemineralsboronhtm[32] M A Halim R K Majumder S A Nessa et al ldquoEvaluation
of processes controlling the geochemical constituents in deepgroundwater in Bangladesh spatial variability on arsenic andboron enrichmentrdquo Journal of HazardousMaterials vol 180 no1ndash3 pp 50ndash62 2010
[33] J BuschmannM Berg C Stengel andM L Sampson ldquoArsenicand manganese contamination of drinking water resources inCambodia coincidence of risk areaswith low relief topographyrdquoEnvironmental Science and Technology vol 41 no 7 pp 2146ndash2152 2007
[34] R A Beckman A S Mildvan and L A Loeb ldquoOn the fidelityof DNA replication manganese mutagenesis in vitrordquo Biochem-istry vol 24 no 21 pp 5810ndash5817 1985
[35] S-H Kim K Kim K-S Ko Y Kim and K-S Lee ldquoCo-con-tamination of arsenic andfluoride in the groundwater of uncon-solidated aquifers under reducing environmentsrdquoChemospherevol 87 no 8 pp 851ndash856 2012
Figure 2 Piper diagram showing the chemical compositions of groundwater samples
(1199032 = 091 1199032 = 069) and sulfate versus EC and sodium(1199032 = 062 1199032 = 061) which is related to the predominanceof sodium chloride types in groundwater with higher salinitySodium bicarbonate waters are related generally with lowsalinity samples in analyzed groundwater samples the ECshows poor correlation with HCO
3
minus (1199032 = 021)Results of chemical analysis show large variations in
chemical composition and also indicate the high salinity ofmany of the groundwater samples According to Larroza andFarina [19] the salinity of groundwater in the basin of theChaco region is due to the previous existence of a shallowsea of restricted environment which has left its salts thisgeographical feature called Paranaense Sea has originatedduring the Middle and Upper Miocene The extremelyheterogeneous values of EC from groundwater could beexplained by the local variation in sedimentary and hydro-geological characteristics [13] Moreover the evaporation inarid and semiarid zones favors the increase of salinity andalkalinity [15 22]
32 Total Arsenic and Fluoride Arsenic is classified as ahuman carcinogen (Type A) based on sufficient epidemio-logic evidence linking increased mortality from liver kidneybladder and lung cancers to drinking As-contaminatedwater[23] The provisional guideline value recommended by theWHO [5] for this carcinogenic contaminant in drinkingwater is 10 120583g Lminus1 and in Argentina this would be enforcedin 2017 [24] On the basis of this criterion only 9 (445)of groundwater source is within levels recommended forconsumption whereas about 73 (3345) of all analyzedsamples showed As values above 50 120583g Lminus1 (CAA) [25]Mean concentration of total arsenic in groundwater was213 120583g Lminus1 and maximum was 1990120583g Lminus1 (Table 2) Thehighest As concentrationwas found in groundwater collectedin sample M36 The presence of arsenic in the groundwatersamples collected from this region of Argentina is naturalthe local geology and rainfall have been shown to havemajor impact on the variations of As concentration ingroundwater
6 ISRN Environmental Chemistry
Table 2 Statistical summary of the chemistry of groundwater (major ions and trace elements 119899 = 45) from Comandante Fernandez Depart-ment Chaco Northeast Argentina
Parameter Mean Median Range 10th percentil 90th percentil Standard deviationDepth (m) 220 130 500ndash220 800 500 331pH 754 751 650ndash894 690 822 055EC (mScm) 527 250 069ndash249 099 134 628HCO
Different positive correlation were observed in ground-water between As versus HCO
3
minus and Na+ (1199032 = 075 1199032 =045) and a negative correlation was found between As andCa2+ (1199032 = minus005) It could be assumed that As is associatedwith NandashHCO
3
minus system related to feldspar dissolution [26]Based on values of pH found in groundwater of this region ofChaco including data reported from other sites of the region[1 13 27] it can be presumed that pH controls As mobility
The study made by Smedley et al [28] reveals that highlyAs(V)-contaminated groundwater in oxidizing environmentsthroughout the world are characterized by high concen-tration of HCO
3
minus (gt500mg Lminus1) and SO4
2minus (gt250mg Lminus1)and pH gt 750 Similar geochemical conditions occur in theChaco-Pampean plain like in the arid regions of Santiagodel Estero Cordoba y La Pampa [13 14 27] High As con-centrations are common and dominated by As(V) and thegroundwater have correspondingly high F concentrationsThese general characteristic are consistent with the analyzed
groundwater However arsenic speciation is not performedin the present study
On the other hand smaller quantities of fluoride ion inthe order of 1mg Lminus1 in ingested water are usually consideredto have a beneficial effect by lowering the rate of occurrenceof dental caries Excessive intake (gt15mg Lminus1) would resultsin pathological changes in teeth and bones such as mottlingof teeth or dental fluorosis along with metabolic changesreported on soft tissues such as thyroid reproductive organsbrain liver and kidneys [29]
TheWHOguideline value for F concentration in drinkingwater is 15mg Lminus1 [5] whereas the Codigo AlimentarioArgentino (CCA) [25] establishes a limit that varies accordingto the average temperature of the place (1mg Lminus1 for an aver-age temperature of 215∘C in the area under study) Thedistribution of F concentrations is heterogeneous and similarto As A positive correlation was observed between As andF with 1199032 = 050 The analyzed groundwater 31 (1445) of
ISRN Environmental Chemistry 7
the samples exceeded theWHO guideline value of 15mg Lminus1[5] About 47 of all analyzed samples showed F values above1mg Lminus1 recommended by CAA (Table 4) Similar correla-tions between As and F were also observed in groundwaterfrom neighboring Santiago del Estero [13] Santa Fe [14] andSalta Provinces [30]
In the same way as arsenic the F rich water is character-ized by high concentration of Na+ and low concentration ofCa2+ and Mg2+ (1199032 = 045 009 and 016 resp) Fluoride is ahighly reactive element that combines with other elements incovalent and ionic bonds It is mainly found in alkaline rocksand alkaline soils fluorite being the principal componentGomez et al [27] explain that the processes that could controlthe low relationship between F and Ca2+ and the positiverelationship between F and bicarbonate (1199032 = 024) would bethe balance equation relating calcite and fluorite when bothare in contact with water
As and other trace elements such as V Mo U and minorelements such as B and F are presumed to have their originalsource in volcanic ashes originated from the volcanismin the Andes (5ndash25 in the loess-type sediments of theChaco-Pampean plain) [9] The main components of thesesediments are feldspars quartz volcanic glass shards andminor amounts of muscovite and calcite The compositionof volcanic glass is typically rhyolitic containing a highconcentration of F As V and B among other trace elements[28]
33 Other Trace Elements A series of various trace elementsincluding Ag Al B Ba Be Cd Co Cr Cu Fe Mn MoNi P Pb S Sb Se Si Sr Ti V and Zn were also deter-mined in the studied groundwater The concentrations oftarget elements are summarized in Table 3 Among all 23target analytes concentrations exceeding the WHO recom-mended drinking water limits (in parentheses) were foundfor B (2400120583g Lminus1) Ba (700 120583g Lminus1) Cd (3 120583g Lminus1) and Sb(20120583g Lminus1) Table 4 shows the percentage of groundwatersamples exceeding these WHO and CAA elemental concen-tration guidelines On the other hand concentrations of SnCo Cu Ni S Se Sr V and Zn were very low Silver beryl-lium chrome selenium lead and titanium are not includ inTables 2 and 3 because these elements were never found aboverespective quantification limits
From the samples investigated only one (M45) showedelevated value of barium (1400 120583g Lminus1) than in the WHOdrinking water guideline (700 120583g Lminus1) with an average valueof 122120583g Lminus1 (Table 2)
In small quantities B is essential for healthy bones jointfunction and the metabolism of steroidal hormonesBoron deficiency seems to affect calcium and magnesiummetabolism and affects the composition structure andstrength of bone [31]The concentrations of boron (B) rangedfrom 1560 to 21910 120583g Lminus1 with an average of 4020120583g Lminus1(Table 2) Boron concentration in the 44 (2045) ofthe samples exceeds the WHO and 78 (3545) of thesamples exceeds the CAA standard limits for drinking water(Table 4) The highest concentration of boron was observedin sample M40 which is associated with the largest value
of EC (19371 120583S cmminus1) In general the presence of boron ingroundwater depends on its salinity (represented as EC) suchthat it increases with increasing salinity [32] In this studya positive correlation between EC and boron (1199032 = 064)suggests that boron might be associated with the salinity ofthese samplesHence the salinitymainly reflects the variationof Clminus concentration with a strong linear correlation(1199032 = 091) between EC and Clminus suggesting that the increaseof Clminus concentration contributes to increase in EC valueThehydraulic conductivity salinity type of clay sediments pHand temperature are the crucial factors that determine boronmobility in the groundwater system [32] Boron was stronglycorrelated with Na+ K+ Mg2+ Clminus SO
4
2minus HCO3
minus andAs probably due to their common origin The correlationbetween B and As is often observed in groundwater [1 13]
Our results indicate that approximately 31 of thegroundwater samples tested exceeded the CAA criteria of300 120583g Lminus1 for total Fe in drinking water The highest totalFe concentration (2000120583g Lminus1) appeared in sample M38 Ingeneral Fe concentrationwas low in the studied groundwatersamples only fourteen samples had higher Fe with a meanvalue of 276120583g Lminus1 and median value of 81 120583g Lminus1 On theother hand weaker correlation is observed between Fe andAsin groundwater (1199032 = 017) Moreover almost all groundwa-ter with high Fe concentration (gt300120583g Lminus1) contained totalAs concentration over 10 120583g Lminus1 (Table 3)
The concentration of dissolved Al varied between 600to 17380 120583g Lminus1 with a mean value of 561120583g Lminus1 (Table 2)A 16 (745) exceeded the 200120583g Lminus1 CAA drinking waterguideline However the mean concentration of Al decreasessignificantly down to 178120583g Lminus1 (median 985120583g Lminus1) if theanomalous of sample M24 is excluded Also Aluminumshows no correlation with As (1199032 = minus006)
Manganese exceeded the 100 120583g Lminus1 CAA drinking waterguideline value in 13 (645) of the samples (Tables 3 and4) The highest Mn concentration (3740 120583g Lminus1) was foundin sample M32 However the mean concentration of Mndecreases significantly from 152 to 700 120583g Lminus1 (median500120583g Lminus1) if the anomalous value of this sample is exclud-ed Manganese shows no correlation with As (1199032 = minus007)Mn is known as an essential element for human survivalserves as a catalyst and cofactor in many enzymatic processesinvolved in the synthesis of fatty acids and cholesterol Thechronic ingestion of Mn in drinking water is associated withneurologic damage [33] Moreover manganese is a knownmutagen [34]
Many samples have Fe Al and Mn concentrationsbelow detection limits and most have below CAA guidelinevalue However concentrations are higher in a few samples(Table 2) Smedley et al [1] suggest that at the pH of thegroundwater the high concentrations for these elements traceare most likely due to presence of colloidal particles As thegroundwater are oxidizing solubility of Fe Al andMnoxidesis low and concentrations of dissolved Fe Al and Mn aretherefore mostly low
The processes of dissolution and release from oxides andoxyhydroxides mainly Al Mn and Fe control the presence
8 ISRN Environmental Chemistry
Table3Tracee
lementcom
positionof
grou
ndwater
samples
from
theC
omandanteF
ernand
ezDepartm
entCh
aco
SampleID
As(to
t)F
Al
FeMn
BBa
Mo
SiV
Cd
SrCo
Ni
ZnCu
SP (
tot)
SbQL
500
010
100
100
500
200
100
100
500
100
300
250
100
100
100
100
0025
010
250
M1
500
190
110
600
500
1598
bql
126
bql
830
500
730
bql
bql
bql
bql
110
080
bql
M2
250
050
120
401
bql
310
156
bql
309
450
bql
420
bql
bql
bql
bql
200
030
bql
M3
100
180
900
160
300
875
bql
bql
bql
100
bql
691
bql
bql
300
bql
107
290
bql
M4
150
030
100
bql
bql
206
bql
bql
bql
220
bql
290
bql
bql
bql
bql
700
030
bql
M5
127
074
220
bql
900
811
791
420
227
119bq
l594
bql
bql
410
bql
020
090
bql
M6
580
080
110
bql
bql
297
100
bql
bql
440
bql
498
bql
bql
bql
bql
700
050
bql
M7
240
040
100
bql
bql
275
482
120
bql
430
bql
230
bql
bql
bql
bql
800
030
bql
M8
120
100
100
bql
600
2654
790
bql
2099
900
300
2012
bql
bql
bql
bql
110
080
bql
M9
178
198
130
550
700
1550
101
990
549
163
700
811
bql
bql
bql
630
700
080
900
M10
500
260
800
220
870
15070
bql
160
16570
390
400
4871
bql
bql
bql
bql
725
190
bql
M11
250
224
100
bql
600
1387
bql
140
480
230
bql
641
bql
bql
bql
bql
132
050
bql
M12
110
044
100
bql
194
500
620
bql
114530
bql
334
bql
100
bql
bql
130
060
bql
M13
952
110
110
bql
500
500
269
420
bql
760
400
683
bql
bql
bql
bql
100
030
300
M14
11615
0110
bql
500
665
bql
431
bql
650
500
540
bql
bql
bql
bql
700
070
bql
M15
310
050
102
500
500
2449
402
303
680
570
bql
521
bql
bql
bql
bql
490
060
bql
M16
290
040
130
150
500
255
518
bql
490
110
bql
362
bql
bql
bql
bql
260
030
bql
M17
830
120
100
bql
bql
1782
403
bql
3940
940
300
1427
bql
bql
bql
bql
113
020
300
M18
620
080
700
bql
182
734
bql
bql
2550
280
bql
2510
bql
bql
bql
bql
281
060
bql
M19
100
020
110
bql
500
298
144
bql
bql
300
bql
157
bql
bql
bql
bql
800
050
bql
M20
112
145
100
bql
bql
2316
220
109
4750
112
300
1390
bql
bql
bql
bdl
147
040
bql
M21
700
190
100
bql
254
2470
bql
112
353
280
bql
1361
bql
bql
bql
bql
415
890
bql
M22
100
020
100
bql
292
156
169
bql
bql
bql
bql
860
bql
bql
bql
bql
600
150
bql
M23
360
030
110
bql
bql
630
109
bql
bql
300
bql
225
bql
bql
bql
bql
500
070
900
M24
860
075
17380
310
296
21560
111
bql
1380
120
300
324
bql
bql
321
bql
010
080
bql
M25
770
120
2980
bql
521
6308
bql
bql
1647
220
Bql
bql
bql
100
2831
320
010
250
400
M26
100
340
600
110
bql
1800
150
210
150
198
300
150
bql
bql
bql
bql
006
180
bql
M27
214
420
600
855
bql
6890
bql
213
150
560
300
213
280
bql
670
280
006
110
bql
M28
100
340
600
428
bql
8450
bql
214
150
219
300
150
220
bql
bql
220
006
670
bql
M29
100
060
600
660
bql
6850
bql
208
150
100
300
150
bql
bql
670
bql
006
770
bql
M30
244
090
600
810
330
3050
185
210
150
547
300
150
bql
bql
240
bql
006
130
250
M31
770
340
280
1013
230
7290
bql
210
150
2646
300
322
bql
bql
bql
bql
030
030
bql
M32
700
010
210
286
3740
5080
632
209
150
bql
300
164
640
bql
110
640
020
230
300
M33
174
170
600
734
321
2790
690
210
7540
266
300
150
bql
bql
270
bql
Bql
220
bql
M34
317
030
360
575
240
1970
118
214
150
436
300
150
bql
bql
bql
bql
040
060
bql
M35
1073
030
600
194
bql
6340
301
205
150
1249
300
150
120
bql
490
120
006
030
300
M36
1990
425
600
510
135580
bql
210
150
251
300
288
240
bql
130
bql
006
530
300
M37
200
030
570
606
131290
113
210
150
387
300
203
240
100
160
670
060
050
bql
M38
150
190
600
2000
bql
3710
bql
210
150
380
300
200
950
bql
bql
bql
006
030
300
M39
200
050
600
300
bql
4830
140
210
150
104
300
200
bql
bql
bql
670
006
990
140
ISRN Environmental Chemistry 9
Table3Con
tinued
SampleID
As(to
t)F
Al
FeMn
BBa
Mo
SiV
Cd
SrCo
Ni
ZnCu
SP (
tot)
SbM40
200
050
600
689
bql
21910
bql
210
150
124
300
200
bql
bql
bql
240
006
130
300
M41
150
150
600
988
bql
21580
bql
210
150
176
300
302
bql
bql
bql
bql
006
110
300
M42
130
080
600
426
bql
1970
bql
210
150
345
300
369
180
bql
270
111
006
020
300
M43
150
140
600
700
431
1030
107
210
150
bql
300
bql
550
bql
220
270
006
080
bql
M44
100
120
600
800
bql
2600
289
210
150
191
300
bql
bql
bql
bql
bql
006
480
bql
M45
200
160
600
262
331
240
1400
210
150
350
300
bql
bql
bql
110490
006
230
bql
QLqu
antifi
ctionlim
itbq
lbello
wqu
antifi
catio
nlim
itallcon
centratio
nsaree
xpressed
as120583gLminus1excepted
forF
Sand
Pexpressedas
mgLminus1
10 ISRN Environmental Chemistry
Table 4 Risk-based drinking water criteria and the percentage ofgroundwater samples exceeding these criteria
NA not applicablelowastWHO World Health Organization have not established risk-based drink-ing water criteria for Al Ag Be Bi Co Fe Mn Mo Si Sr Ti V and ZnlowastlowastCAA Codigo Alimentario ArgentinolowastlowastlowastProvisional guideline value
and mobility of As and F in groundwater [1] Kim et al [35]suggested that the cocontamination of As and F observed inoxidizing aquifers in many countries is associated with thedesorption from the Fe-(hydr) oxides by the pH increasesThe correlations between As and F are generally very high inthose aquifers because the As released from Fe-(hydr) oxidesdoes not readily precipitate again in the oxidizing alkalinecondition This is consistent with our observations as manyof the samples show high pH values and moderate coefficientcorrelation value between As and F (1199032 = 050) Alsosolubility of Al minerals may be enhanced by the complex ofdissolved Al with F that is also released from volcanic glasses
Vanadium in groundwater ranged between lt100 (QL)and 2646 120583g Lminus1 The highest V concentration was found insample M31 (Table 2) Vanadium shows a moderated positivecorrelation with As (1199032 = 042) and is likely to be derivedfrom similar mineral sources (secondary Fe and Mn oxides)under the high pH conditions [1] Our results also indicatethat Mo in general appears in low concentrations (Table 3)Molybdenum is weakly correlated with As (1199032 = 020)
Gomez et al [27] suggest that V U B and Mo areenriched in volcanic materials and are mobilized as vanadatemolybdate borate and so forth under oxidizing conditionsAlternatively they are mobilized in alkaline solutions under
conditions of high pH and high HCO3
minus controlled bycarbonate reactions (eg the F may be forming anioniccomplexes with B Fe and Al)
Antimony (Sb) is ubiquity a GroupV of the periodic tableand is similar to As in aspects as chemical behavior andtoxicity to animals [5] The Sb concentrations in studiedsamples exceeded 20120583g Lminus1 WHO and CAA drinking waterguideline values in 45 (245) of the analyzed samples(Tables 3 and 4)
Cadmium reaches a maximum of 70120583g Lminus1 with mostsamples being less than 30 120583g Lminus1 As this element formscationic species in solution its mobilization is not favoredunder the alkaline conditions of the groundwater [1]
The presence of arsenic and heavy metals in the samplescollected from this region of Chaco in Argentina may be dueto local geochemical conditions that facilitate the transfer ofnaturally occurring arsenic from soil and sediment to thewaterThe people in the Comandante FernandezDepartmentmay be overexposed not only toAs but also to B CdMn andF Adverse health effects may appear in coming years Thisproblem is a serious concern for the local population
4 Conclusions
The results of the current study indicate that approximately91 of the groundwater samples used for consumptionby human and livestock from the Comandante FernandezDepartment (Chaco province Argentina) exceed the WHOprovisional guideline value of 10 120583g Lminus1 As recommended asa maximum allowable level in potable water
Evaporation potentiated in arid and semiarid zonefavors the increase of salinity and alkalinity the results is alow quality of the resource but is not conditioning the con-centration of As and F Hence factors other than evaporationsuch as desorption from metal oxides and possibly silicatereaction could be likely controlling As and F mobiliza-tion Furthermore arsenic associated trace elements may beabsorbed on the surface of iron and aluminum oxides andoxyhydroxides (hematite goethite Fe(OH)
3
and gibbsite)limiting the mobility of trace elements Groundwater withhigh pH values and high concentration of bicarbonate wouldfacilitate the dissolution of volcanic glass thus trace elementsmay enter groundwater cycles forming anionic complexes inalkaline solutions and acquiring great mobility
The hydrochemical trace in the region is characterizedby high salinity and high As and F concentrations whichis related to volcanism and hydrothermal activity from theAndes This association is often linked to presence of BCd Mo Mn and V indicating their common origin in thevolcanic glasses
Due to high As concentrations found in groundwaterserious health risk must be considered The population inthe area may be exposed to the chronic toxicological effectsof hydro arsenicism and fluorosis increasing the risks ofcontracting other diseases derived from them Since thegroundwater studied here constitutes the principal source ofdrinking water in the zone mitigation efforts should not belimited to As health risks from other toxic elements presentin drinking water must also be addressed in this region
ISRN Environmental Chemistry 11
Conflict of Interest
The authors declare that there is no conflict of interestsregarding the publication of this paper Its publication isapproved by all authors and tacitly or explicitly by the respon-sible authorities where the work was carried out and that ifaccepted it will not be published elsewhere in the same formin English or in any other language including electronicallywithout the written consent of the copyright-holder
Acknowledgments
This work was supported with funds from PI 3600005 Uni-versidad Nacional del Chaco Austral (UNCAus) Patricia SBlanes thanks the National Academy of Exact Physic andNatural Sciences for granting a PhD fellowship
References
[1] P L Smedley H B Nicolli DM JMacdonald A J Barros andJ O Tullio ldquoHydrogeochemistry of arsenic and other inorganicconstituents in groundwaters from La Pampa ArgentinardquoApplied Geochemistry vol 17 no 3 pp 259ndash284 2002
[2] S Muhammad M T Shah and S Khan ldquoHealth risk assess-ment of heavy metals and their source apportionment in drink-ingwater of Kohistan region northern PakistanrdquoMicrochemicalJournal vol 98 no 2 pp 334ndash343 2011
[3] S S Farıas V A Casa C Vazquez L Ferpozzi G N Pucci andI M Cohen ldquoNatural contamination with arsenic and othertrace elements in ground waters of Argentine Pampean PlainrdquoScience of the Total Environment vol 309 no 1ndash3 pp 187ndash1992003
[4] L Jarup ldquoHazards of heavy metal contaminationrdquo British Med-ical Bulletin vol 68 pp 167ndash182 2003
[5] World Health Organization (WHO) ldquoRecommendationsrdquo inGuidelines for Drinking Water Quality vol 1 Geneva Switzer-land 4th edition 2011
[6] C Hopenhayn ldquoArsenic in drinking water impact on humanhealthrdquo Elements vol 2 no 2 pp 103ndash107 2006
[7] S H Lamm and M B Kruse ldquoArsenic ingestion and bladdercancermortalitymdashwhat do the dose-response relationships sug-gest aboutmechanismrdquoHumanandEcological RiskAssessmentvol 11 no 2 pp 433ndash450 2005
[8] C-HWang C K Hsiao C-L Chen et al ldquoA review of the epi-demiologic literature on the role of environmental arsenicexposure and cardiovascular diseasesrdquo Toxicology and AppliedPharmacology vol 222 no 3 pp 315ndash326 2007
[9] J Bundschuh M I Litter F Parvez et al ldquoOne century ofarsenic exposure in Latin America a review of history andoccurrence from 14 countriesrdquo Science of the Total Environmentvol 429 pp 2ndash35 2012
[10] M T Alarcon-Herrera J Bundschuh B Nath et al ldquoCo-occurrence of arsenic and fluoride in groundwater of semi-aridregions in Latin America genesis mobility and remediationrdquoJournal of Hazardous Materials 2012
[11] E E Buchhamer P S Blanes RM Osicka andM C GimenezldquoEnvironmental risk assessment of arsenic and fluoride in thechaco province argentina research advancesrdquo Journal of Toxi-cology and Environmental Health A vol 75 no 22-23 pp 1437ndash1450 2012
[12] A Cabrera M Blarasin E Matteoda G Villalva and M LGomez ldquoComposicion quımica del agua subterranea en el surde Cordoba lınea de base hidroquımica o fondo natural enreferencia a arsenico y fluorrdquo in Aguas Superficiales y Sub-terraneas en el sur ae Cordoba Una Perspectiva GeoambientalM Blarasin S Degiovanni A Cabera and M Villegas Edspp 81ndash90 Universidad Nacional de Rıo Cuarto Rıo CuartoArgentina 2005
[13] P Bhattacharya M Claesson J Bundschuh et al ldquoDistributionand mobility of arsenic in the Rıo Dulce alluvial aquifers inSantiago del Estero Province Argentinardquo Science of the TotalEnvironment vol 358 no 1ndash3 pp 97ndash120 2006
[14] B Nicolli O C Tujchneider M C Paris M Blanco and A JBarros ldquoMovilidad del arsenico y oligoelementos asociados enaguas subterraneas del centro-norte de la provincia de Santa FeArgentinardquo in Proceedings of the Presencia de Fluor y Arsenicoen Aguas Subterraneas VI Congreso Hidrogeologico ArgentinoG Galindo J L Fernandez Turiel and A Storniolo Eds pp81ndash90 Santa Rosa La Pampa Argentina 2009
[15] H B Nicolli A Tineo J W Garcıa C M Falcon and PL Smedley ldquoMobilization of arsenic and other trace elementof health concern in groundwater from the Salı River BasinTucuman Province Argentinardquo Environmental Geochemistryand Health vol 34 no 2 pp 251ndash262 2012
[16] RMOsicka N Agullo C Herrera Ahuad andMC GimenezldquoEvaluacion de las concentraciones de fluoruro y arsenico enlas aguas subterraneas del Domo Central de la provincia delChacordquo Comunicaciones Cientıficas y Tecnologicas Univer-sidad Nacional del Nordeste 2002 httpwwwunneeduarunneviejaWebcytcyt200208-ExactasE-049pdf
[17] C E Fiorentino J D Paoloni M E Sequeira and P ArosteguyldquoThe presence of vanadium in groundwater of southeasternextreme the pampean region Argentina Relationship withother chemical elementsrdquo Journal of Contaminant Hydrologyvol 93 no 1ndash4 pp 122ndash129 2007
[18] P Sprechmann F G Acenaloza C Gaucher A C R Nogueiraand M J Perez ldquoTrasgresion Paranaense paleoestuario deltethys del miocenomedio yo superior en Sudamericardquo in Con-greso Latinoamericano de Geologıa Montevideo-UruguayAbstracts 1 CDRoom pp 10ndash15 Sociedad Latinoamericana deGeologıa 2001
[19] F Larroza and L S Farina ldquoCaracterizacion hidrogeologica delsistema acuıfero Yrenda (SAY) en Paraguay recurso compar-tido con y Boliviardquo in Proceedings of the IV Congreso Argentinode Hidrogeologıa TOMO II Argentinarıo Cuarto CordobaArgentina 2005
[20] E Popolizio P Y Serra and G O Hort ldquoLa clasificaciontaxonomica del Chacordquo Centro de Geociencia Aplicada vol 3no 1 pp 11ndash32 1980
[21] INTA ldquoInstituto Nacional de Tecnologıa AgropecuariardquoAgrometeorologıa httpwwwintagovarsaenzpemeteorolo-giameteorologiahtm
[22] M G Garcıa O Sracek D S Fernandez andM D V HidalgoldquoFactors affecting arsenic concentration in groundwaters fromNorthwestern Chaco-Pampean Plain Argentinardquo Environmen-tal Geology vol 52 no 7 pp 1261ndash1275 2007
[23] US Environmental Protection Agency ( EPA) ldquoArsenic Inor-ganic United States Environmental Protection Agency Inte-grated Risk Information System (IRIS) (CASRN 7440-38-2)rdquo1998 httpwwwepagovirissubst0278htm
12 ISRN Environmental Chemistry
[24] Comision Nacional de Alimentos (CONAL) Acta Nž 93Reunion Ordinaria 3011 y 0112-2011 (Prorroga Art 982 y 983del CAA)
[25] CAA (Codigo Alimentario Argentino) Cap XII Bebidashıdricas agua y agua gasificada In Codigo Alimentario Argen-tino modificatoria del Art 982 (Res 682007 y 1962007) Ley18 284 Buenos Aires Argentina 2007 httpwwwanmatgovarCODIGOACapitulo XII Agua 2007-05pdf
[26] J L Fernandez Turiel G GalindoM A Parada D GimenoMGarcıa-Valles and J Saavedra ldquoEstado actual del conocimientosobre el arsenico en el agua de Argentina y Chile origenmovilidad y transporterdquo inArsenico en Agua Origen movilidady tratamiento II Seminario Hispano-Latinoamericano sobreTemas Actuales de Hidrologıa Subterranea y IV Congreso Hidro-geologico Argentino pp 1ndash22 Rıo Cuarto Argentina 2005
[27] M L Gomez M T Blarasin and D E Martınez ldquoArsenic andfluoride in a loess aquifer in the central area of Argentinardquo Envi-ronmental Geology vol 57 no 1 pp 143ndash155 2009
[28] P L Smedley D G Kinniburgh D M J Macdonald et alldquoArsenic associations in sediments from the loess aquifer of LaPampa Argentinardquo Applied Geochemistry vol 20 no 5 pp989ndash1016 2005
[29] D L Ozsvath ldquoFluoride and environmental health a reviewrdquoReviews in Environmental Science and Biotechnology vol 8 no1 pp 59ndash79 2009
[30] E M Farfan Torres P M Naranjo A Boemo I Lomnicziand L Lorenzo ldquoDistribution of arsenic in groundwater in theChaco Salteno Argentinardquo in Workshop on as Distribution inIbero-America M I Litter Ed CyTED IBEROARSENAbstractBook pp 57ndash60 2006
[31] httpwwwjctoniccomincludemineralsboronhtm[32] M A Halim R K Majumder S A Nessa et al ldquoEvaluation
of processes controlling the geochemical constituents in deepgroundwater in Bangladesh spatial variability on arsenic andboron enrichmentrdquo Journal of HazardousMaterials vol 180 no1ndash3 pp 50ndash62 2010
[33] J BuschmannM Berg C Stengel andM L Sampson ldquoArsenicand manganese contamination of drinking water resources inCambodia coincidence of risk areaswith low relief topographyrdquoEnvironmental Science and Technology vol 41 no 7 pp 2146ndash2152 2007
[34] R A Beckman A S Mildvan and L A Loeb ldquoOn the fidelityof DNA replication manganese mutagenesis in vitrordquo Biochem-istry vol 24 no 21 pp 5810ndash5817 1985
[35] S-H Kim K Kim K-S Ko Y Kim and K-S Lee ldquoCo-con-tamination of arsenic andfluoride in the groundwater of uncon-solidated aquifers under reducing environmentsrdquoChemospherevol 87 no 8 pp 851ndash856 2012
Table 2 Statistical summary of the chemistry of groundwater (major ions and trace elements 119899 = 45) from Comandante Fernandez Depart-ment Chaco Northeast Argentina
Parameter Mean Median Range 10th percentil 90th percentil Standard deviationDepth (m) 220 130 500ndash220 800 500 331pH 754 751 650ndash894 690 822 055EC (mScm) 527 250 069ndash249 099 134 628HCO
Different positive correlation were observed in ground-water between As versus HCO
3
minus and Na+ (1199032 = 075 1199032 =045) and a negative correlation was found between As andCa2+ (1199032 = minus005) It could be assumed that As is associatedwith NandashHCO
3
minus system related to feldspar dissolution [26]Based on values of pH found in groundwater of this region ofChaco including data reported from other sites of the region[1 13 27] it can be presumed that pH controls As mobility
The study made by Smedley et al [28] reveals that highlyAs(V)-contaminated groundwater in oxidizing environmentsthroughout the world are characterized by high concen-tration of HCO
3
minus (gt500mg Lminus1) and SO4
2minus (gt250mg Lminus1)and pH gt 750 Similar geochemical conditions occur in theChaco-Pampean plain like in the arid regions of Santiagodel Estero Cordoba y La Pampa [13 14 27] High As con-centrations are common and dominated by As(V) and thegroundwater have correspondingly high F concentrationsThese general characteristic are consistent with the analyzed
groundwater However arsenic speciation is not performedin the present study
On the other hand smaller quantities of fluoride ion inthe order of 1mg Lminus1 in ingested water are usually consideredto have a beneficial effect by lowering the rate of occurrenceof dental caries Excessive intake (gt15mg Lminus1) would resultsin pathological changes in teeth and bones such as mottlingof teeth or dental fluorosis along with metabolic changesreported on soft tissues such as thyroid reproductive organsbrain liver and kidneys [29]
TheWHOguideline value for F concentration in drinkingwater is 15mg Lminus1 [5] whereas the Codigo AlimentarioArgentino (CCA) [25] establishes a limit that varies accordingto the average temperature of the place (1mg Lminus1 for an aver-age temperature of 215∘C in the area under study) Thedistribution of F concentrations is heterogeneous and similarto As A positive correlation was observed between As andF with 1199032 = 050 The analyzed groundwater 31 (1445) of
ISRN Environmental Chemistry 7
the samples exceeded theWHO guideline value of 15mg Lminus1[5] About 47 of all analyzed samples showed F values above1mg Lminus1 recommended by CAA (Table 4) Similar correla-tions between As and F were also observed in groundwaterfrom neighboring Santiago del Estero [13] Santa Fe [14] andSalta Provinces [30]
In the same way as arsenic the F rich water is character-ized by high concentration of Na+ and low concentration ofCa2+ and Mg2+ (1199032 = 045 009 and 016 resp) Fluoride is ahighly reactive element that combines with other elements incovalent and ionic bonds It is mainly found in alkaline rocksand alkaline soils fluorite being the principal componentGomez et al [27] explain that the processes that could controlthe low relationship between F and Ca2+ and the positiverelationship between F and bicarbonate (1199032 = 024) would bethe balance equation relating calcite and fluorite when bothare in contact with water
As and other trace elements such as V Mo U and minorelements such as B and F are presumed to have their originalsource in volcanic ashes originated from the volcanismin the Andes (5ndash25 in the loess-type sediments of theChaco-Pampean plain) [9] The main components of thesesediments are feldspars quartz volcanic glass shards andminor amounts of muscovite and calcite The compositionof volcanic glass is typically rhyolitic containing a highconcentration of F As V and B among other trace elements[28]
33 Other Trace Elements A series of various trace elementsincluding Ag Al B Ba Be Cd Co Cr Cu Fe Mn MoNi P Pb S Sb Se Si Sr Ti V and Zn were also deter-mined in the studied groundwater The concentrations oftarget elements are summarized in Table 3 Among all 23target analytes concentrations exceeding the WHO recom-mended drinking water limits (in parentheses) were foundfor B (2400120583g Lminus1) Ba (700 120583g Lminus1) Cd (3 120583g Lminus1) and Sb(20120583g Lminus1) Table 4 shows the percentage of groundwatersamples exceeding these WHO and CAA elemental concen-tration guidelines On the other hand concentrations of SnCo Cu Ni S Se Sr V and Zn were very low Silver beryl-lium chrome selenium lead and titanium are not includ inTables 2 and 3 because these elements were never found aboverespective quantification limits
From the samples investigated only one (M45) showedelevated value of barium (1400 120583g Lminus1) than in the WHOdrinking water guideline (700 120583g Lminus1) with an average valueof 122120583g Lminus1 (Table 2)
In small quantities B is essential for healthy bones jointfunction and the metabolism of steroidal hormonesBoron deficiency seems to affect calcium and magnesiummetabolism and affects the composition structure andstrength of bone [31]The concentrations of boron (B) rangedfrom 1560 to 21910 120583g Lminus1 with an average of 4020120583g Lminus1(Table 2) Boron concentration in the 44 (2045) ofthe samples exceeds the WHO and 78 (3545) of thesamples exceeds the CAA standard limits for drinking water(Table 4) The highest concentration of boron was observedin sample M40 which is associated with the largest value
of EC (19371 120583S cmminus1) In general the presence of boron ingroundwater depends on its salinity (represented as EC) suchthat it increases with increasing salinity [32] In this studya positive correlation between EC and boron (1199032 = 064)suggests that boron might be associated with the salinity ofthese samplesHence the salinitymainly reflects the variationof Clminus concentration with a strong linear correlation(1199032 = 091) between EC and Clminus suggesting that the increaseof Clminus concentration contributes to increase in EC valueThehydraulic conductivity salinity type of clay sediments pHand temperature are the crucial factors that determine boronmobility in the groundwater system [32] Boron was stronglycorrelated with Na+ K+ Mg2+ Clminus SO
4
2minus HCO3
minus andAs probably due to their common origin The correlationbetween B and As is often observed in groundwater [1 13]
Our results indicate that approximately 31 of thegroundwater samples tested exceeded the CAA criteria of300 120583g Lminus1 for total Fe in drinking water The highest totalFe concentration (2000120583g Lminus1) appeared in sample M38 Ingeneral Fe concentrationwas low in the studied groundwatersamples only fourteen samples had higher Fe with a meanvalue of 276120583g Lminus1 and median value of 81 120583g Lminus1 On theother hand weaker correlation is observed between Fe andAsin groundwater (1199032 = 017) Moreover almost all groundwa-ter with high Fe concentration (gt300120583g Lminus1) contained totalAs concentration over 10 120583g Lminus1 (Table 3)
The concentration of dissolved Al varied between 600to 17380 120583g Lminus1 with a mean value of 561120583g Lminus1 (Table 2)A 16 (745) exceeded the 200120583g Lminus1 CAA drinking waterguideline However the mean concentration of Al decreasessignificantly down to 178120583g Lminus1 (median 985120583g Lminus1) if theanomalous of sample M24 is excluded Also Aluminumshows no correlation with As (1199032 = minus006)
Manganese exceeded the 100 120583g Lminus1 CAA drinking waterguideline value in 13 (645) of the samples (Tables 3 and4) The highest Mn concentration (3740 120583g Lminus1) was foundin sample M32 However the mean concentration of Mndecreases significantly from 152 to 700 120583g Lminus1 (median500120583g Lminus1) if the anomalous value of this sample is exclud-ed Manganese shows no correlation with As (1199032 = minus007)Mn is known as an essential element for human survivalserves as a catalyst and cofactor in many enzymatic processesinvolved in the synthesis of fatty acids and cholesterol Thechronic ingestion of Mn in drinking water is associated withneurologic damage [33] Moreover manganese is a knownmutagen [34]
Many samples have Fe Al and Mn concentrationsbelow detection limits and most have below CAA guidelinevalue However concentrations are higher in a few samples(Table 2) Smedley et al [1] suggest that at the pH of thegroundwater the high concentrations for these elements traceare most likely due to presence of colloidal particles As thegroundwater are oxidizing solubility of Fe Al andMnoxidesis low and concentrations of dissolved Fe Al and Mn aretherefore mostly low
The processes of dissolution and release from oxides andoxyhydroxides mainly Al Mn and Fe control the presence
8 ISRN Environmental Chemistry
Table3Tracee
lementcom
positionof
grou
ndwater
samples
from
theC
omandanteF
ernand
ezDepartm
entCh
aco
SampleID
As(to
t)F
Al
FeMn
BBa
Mo
SiV
Cd
SrCo
Ni
ZnCu
SP (
tot)
SbQL
500
010
100
100
500
200
100
100
500
100
300
250
100
100
100
100
0025
010
250
M1
500
190
110
600
500
1598
bql
126
bql
830
500
730
bql
bql
bql
bql
110
080
bql
M2
250
050
120
401
bql
310
156
bql
309
450
bql
420
bql
bql
bql
bql
200
030
bql
M3
100
180
900
160
300
875
bql
bql
bql
100
bql
691
bql
bql
300
bql
107
290
bql
M4
150
030
100
bql
bql
206
bql
bql
bql
220
bql
290
bql
bql
bql
bql
700
030
bql
M5
127
074
220
bql
900
811
791
420
227
119bq
l594
bql
bql
410
bql
020
090
bql
M6
580
080
110
bql
bql
297
100
bql
bql
440
bql
498
bql
bql
bql
bql
700
050
bql
M7
240
040
100
bql
bql
275
482
120
bql
430
bql
230
bql
bql
bql
bql
800
030
bql
M8
120
100
100
bql
600
2654
790
bql
2099
900
300
2012
bql
bql
bql
bql
110
080
bql
M9
178
198
130
550
700
1550
101
990
549
163
700
811
bql
bql
bql
630
700
080
900
M10
500
260
800
220
870
15070
bql
160
16570
390
400
4871
bql
bql
bql
bql
725
190
bql
M11
250
224
100
bql
600
1387
bql
140
480
230
bql
641
bql
bql
bql
bql
132
050
bql
M12
110
044
100
bql
194
500
620
bql
114530
bql
334
bql
100
bql
bql
130
060
bql
M13
952
110
110
bql
500
500
269
420
bql
760
400
683
bql
bql
bql
bql
100
030
300
M14
11615
0110
bql
500
665
bql
431
bql
650
500
540
bql
bql
bql
bql
700
070
bql
M15
310
050
102
500
500
2449
402
303
680
570
bql
521
bql
bql
bql
bql
490
060
bql
M16
290
040
130
150
500
255
518
bql
490
110
bql
362
bql
bql
bql
bql
260
030
bql
M17
830
120
100
bql
bql
1782
403
bql
3940
940
300
1427
bql
bql
bql
bql
113
020
300
M18
620
080
700
bql
182
734
bql
bql
2550
280
bql
2510
bql
bql
bql
bql
281
060
bql
M19
100
020
110
bql
500
298
144
bql
bql
300
bql
157
bql
bql
bql
bql
800
050
bql
M20
112
145
100
bql
bql
2316
220
109
4750
112
300
1390
bql
bql
bql
bdl
147
040
bql
M21
700
190
100
bql
254
2470
bql
112
353
280
bql
1361
bql
bql
bql
bql
415
890
bql
M22
100
020
100
bql
292
156
169
bql
bql
bql
bql
860
bql
bql
bql
bql
600
150
bql
M23
360
030
110
bql
bql
630
109
bql
bql
300
bql
225
bql
bql
bql
bql
500
070
900
M24
860
075
17380
310
296
21560
111
bql
1380
120
300
324
bql
bql
321
bql
010
080
bql
M25
770
120
2980
bql
521
6308
bql
bql
1647
220
Bql
bql
bql
100
2831
320
010
250
400
M26
100
340
600
110
bql
1800
150
210
150
198
300
150
bql
bql
bql
bql
006
180
bql
M27
214
420
600
855
bql
6890
bql
213
150
560
300
213
280
bql
670
280
006
110
bql
M28
100
340
600
428
bql
8450
bql
214
150
219
300
150
220
bql
bql
220
006
670
bql
M29
100
060
600
660
bql
6850
bql
208
150
100
300
150
bql
bql
670
bql
006
770
bql
M30
244
090
600
810
330
3050
185
210
150
547
300
150
bql
bql
240
bql
006
130
250
M31
770
340
280
1013
230
7290
bql
210
150
2646
300
322
bql
bql
bql
bql
030
030
bql
M32
700
010
210
286
3740
5080
632
209
150
bql
300
164
640
bql
110
640
020
230
300
M33
174
170
600
734
321
2790
690
210
7540
266
300
150
bql
bql
270
bql
Bql
220
bql
M34
317
030
360
575
240
1970
118
214
150
436
300
150
bql
bql
bql
bql
040
060
bql
M35
1073
030
600
194
bql
6340
301
205
150
1249
300
150
120
bql
490
120
006
030
300
M36
1990
425
600
510
135580
bql
210
150
251
300
288
240
bql
130
bql
006
530
300
M37
200
030
570
606
131290
113
210
150
387
300
203
240
100
160
670
060
050
bql
M38
150
190
600
2000
bql
3710
bql
210
150
380
300
200
950
bql
bql
bql
006
030
300
M39
200
050
600
300
bql
4830
140
210
150
104
300
200
bql
bql
bql
670
006
990
140
ISRN Environmental Chemistry 9
Table3Con
tinued
SampleID
As(to
t)F
Al
FeMn
BBa
Mo
SiV
Cd
SrCo
Ni
ZnCu
SP (
tot)
SbM40
200
050
600
689
bql
21910
bql
210
150
124
300
200
bql
bql
bql
240
006
130
300
M41
150
150
600
988
bql
21580
bql
210
150
176
300
302
bql
bql
bql
bql
006
110
300
M42
130
080
600
426
bql
1970
bql
210
150
345
300
369
180
bql
270
111
006
020
300
M43
150
140
600
700
431
1030
107
210
150
bql
300
bql
550
bql
220
270
006
080
bql
M44
100
120
600
800
bql
2600
289
210
150
191
300
bql
bql
bql
bql
bql
006
480
bql
M45
200
160
600
262
331
240
1400
210
150
350
300
bql
bql
bql
110490
006
230
bql
QLqu
antifi
ctionlim
itbq
lbello
wqu
antifi
catio
nlim
itallcon
centratio
nsaree
xpressed
as120583gLminus1excepted
forF
Sand
Pexpressedas
mgLminus1
10 ISRN Environmental Chemistry
Table 4 Risk-based drinking water criteria and the percentage ofgroundwater samples exceeding these criteria
NA not applicablelowastWHO World Health Organization have not established risk-based drink-ing water criteria for Al Ag Be Bi Co Fe Mn Mo Si Sr Ti V and ZnlowastlowastCAA Codigo Alimentario ArgentinolowastlowastlowastProvisional guideline value
and mobility of As and F in groundwater [1] Kim et al [35]suggested that the cocontamination of As and F observed inoxidizing aquifers in many countries is associated with thedesorption from the Fe-(hydr) oxides by the pH increasesThe correlations between As and F are generally very high inthose aquifers because the As released from Fe-(hydr) oxidesdoes not readily precipitate again in the oxidizing alkalinecondition This is consistent with our observations as manyof the samples show high pH values and moderate coefficientcorrelation value between As and F (1199032 = 050) Alsosolubility of Al minerals may be enhanced by the complex ofdissolved Al with F that is also released from volcanic glasses
Vanadium in groundwater ranged between lt100 (QL)and 2646 120583g Lminus1 The highest V concentration was found insample M31 (Table 2) Vanadium shows a moderated positivecorrelation with As (1199032 = 042) and is likely to be derivedfrom similar mineral sources (secondary Fe and Mn oxides)under the high pH conditions [1] Our results also indicatethat Mo in general appears in low concentrations (Table 3)Molybdenum is weakly correlated with As (1199032 = 020)
Gomez et al [27] suggest that V U B and Mo areenriched in volcanic materials and are mobilized as vanadatemolybdate borate and so forth under oxidizing conditionsAlternatively they are mobilized in alkaline solutions under
conditions of high pH and high HCO3
minus controlled bycarbonate reactions (eg the F may be forming anioniccomplexes with B Fe and Al)
Antimony (Sb) is ubiquity a GroupV of the periodic tableand is similar to As in aspects as chemical behavior andtoxicity to animals [5] The Sb concentrations in studiedsamples exceeded 20120583g Lminus1 WHO and CAA drinking waterguideline values in 45 (245) of the analyzed samples(Tables 3 and 4)
Cadmium reaches a maximum of 70120583g Lminus1 with mostsamples being less than 30 120583g Lminus1 As this element formscationic species in solution its mobilization is not favoredunder the alkaline conditions of the groundwater [1]
The presence of arsenic and heavy metals in the samplescollected from this region of Chaco in Argentina may be dueto local geochemical conditions that facilitate the transfer ofnaturally occurring arsenic from soil and sediment to thewaterThe people in the Comandante FernandezDepartmentmay be overexposed not only toAs but also to B CdMn andF Adverse health effects may appear in coming years Thisproblem is a serious concern for the local population
4 Conclusions
The results of the current study indicate that approximately91 of the groundwater samples used for consumptionby human and livestock from the Comandante FernandezDepartment (Chaco province Argentina) exceed the WHOprovisional guideline value of 10 120583g Lminus1 As recommended asa maximum allowable level in potable water
Evaporation potentiated in arid and semiarid zonefavors the increase of salinity and alkalinity the results is alow quality of the resource but is not conditioning the con-centration of As and F Hence factors other than evaporationsuch as desorption from metal oxides and possibly silicatereaction could be likely controlling As and F mobiliza-tion Furthermore arsenic associated trace elements may beabsorbed on the surface of iron and aluminum oxides andoxyhydroxides (hematite goethite Fe(OH)
3
and gibbsite)limiting the mobility of trace elements Groundwater withhigh pH values and high concentration of bicarbonate wouldfacilitate the dissolution of volcanic glass thus trace elementsmay enter groundwater cycles forming anionic complexes inalkaline solutions and acquiring great mobility
The hydrochemical trace in the region is characterizedby high salinity and high As and F concentrations whichis related to volcanism and hydrothermal activity from theAndes This association is often linked to presence of BCd Mo Mn and V indicating their common origin in thevolcanic glasses
Due to high As concentrations found in groundwaterserious health risk must be considered The population inthe area may be exposed to the chronic toxicological effectsof hydro arsenicism and fluorosis increasing the risks ofcontracting other diseases derived from them Since thegroundwater studied here constitutes the principal source ofdrinking water in the zone mitigation efforts should not belimited to As health risks from other toxic elements presentin drinking water must also be addressed in this region
ISRN Environmental Chemistry 11
Conflict of Interest
The authors declare that there is no conflict of interestsregarding the publication of this paper Its publication isapproved by all authors and tacitly or explicitly by the respon-sible authorities where the work was carried out and that ifaccepted it will not be published elsewhere in the same formin English or in any other language including electronicallywithout the written consent of the copyright-holder
Acknowledgments
This work was supported with funds from PI 3600005 Uni-versidad Nacional del Chaco Austral (UNCAus) Patricia SBlanes thanks the National Academy of Exact Physic andNatural Sciences for granting a PhD fellowship
References
[1] P L Smedley H B Nicolli DM JMacdonald A J Barros andJ O Tullio ldquoHydrogeochemistry of arsenic and other inorganicconstituents in groundwaters from La Pampa ArgentinardquoApplied Geochemistry vol 17 no 3 pp 259ndash284 2002
[2] S Muhammad M T Shah and S Khan ldquoHealth risk assess-ment of heavy metals and their source apportionment in drink-ingwater of Kohistan region northern PakistanrdquoMicrochemicalJournal vol 98 no 2 pp 334ndash343 2011
[3] S S Farıas V A Casa C Vazquez L Ferpozzi G N Pucci andI M Cohen ldquoNatural contamination with arsenic and othertrace elements in ground waters of Argentine Pampean PlainrdquoScience of the Total Environment vol 309 no 1ndash3 pp 187ndash1992003
[4] L Jarup ldquoHazards of heavy metal contaminationrdquo British Med-ical Bulletin vol 68 pp 167ndash182 2003
[5] World Health Organization (WHO) ldquoRecommendationsrdquo inGuidelines for Drinking Water Quality vol 1 Geneva Switzer-land 4th edition 2011
[6] C Hopenhayn ldquoArsenic in drinking water impact on humanhealthrdquo Elements vol 2 no 2 pp 103ndash107 2006
[7] S H Lamm and M B Kruse ldquoArsenic ingestion and bladdercancermortalitymdashwhat do the dose-response relationships sug-gest aboutmechanismrdquoHumanandEcological RiskAssessmentvol 11 no 2 pp 433ndash450 2005
[8] C-HWang C K Hsiao C-L Chen et al ldquoA review of the epi-demiologic literature on the role of environmental arsenicexposure and cardiovascular diseasesrdquo Toxicology and AppliedPharmacology vol 222 no 3 pp 315ndash326 2007
[9] J Bundschuh M I Litter F Parvez et al ldquoOne century ofarsenic exposure in Latin America a review of history andoccurrence from 14 countriesrdquo Science of the Total Environmentvol 429 pp 2ndash35 2012
[10] M T Alarcon-Herrera J Bundschuh B Nath et al ldquoCo-occurrence of arsenic and fluoride in groundwater of semi-aridregions in Latin America genesis mobility and remediationrdquoJournal of Hazardous Materials 2012
[11] E E Buchhamer P S Blanes RM Osicka andM C GimenezldquoEnvironmental risk assessment of arsenic and fluoride in thechaco province argentina research advancesrdquo Journal of Toxi-cology and Environmental Health A vol 75 no 22-23 pp 1437ndash1450 2012
[12] A Cabrera M Blarasin E Matteoda G Villalva and M LGomez ldquoComposicion quımica del agua subterranea en el surde Cordoba lınea de base hidroquımica o fondo natural enreferencia a arsenico y fluorrdquo in Aguas Superficiales y Sub-terraneas en el sur ae Cordoba Una Perspectiva GeoambientalM Blarasin S Degiovanni A Cabera and M Villegas Edspp 81ndash90 Universidad Nacional de Rıo Cuarto Rıo CuartoArgentina 2005
[13] P Bhattacharya M Claesson J Bundschuh et al ldquoDistributionand mobility of arsenic in the Rıo Dulce alluvial aquifers inSantiago del Estero Province Argentinardquo Science of the TotalEnvironment vol 358 no 1ndash3 pp 97ndash120 2006
[14] B Nicolli O C Tujchneider M C Paris M Blanco and A JBarros ldquoMovilidad del arsenico y oligoelementos asociados enaguas subterraneas del centro-norte de la provincia de Santa FeArgentinardquo in Proceedings of the Presencia de Fluor y Arsenicoen Aguas Subterraneas VI Congreso Hidrogeologico ArgentinoG Galindo J L Fernandez Turiel and A Storniolo Eds pp81ndash90 Santa Rosa La Pampa Argentina 2009
[15] H B Nicolli A Tineo J W Garcıa C M Falcon and PL Smedley ldquoMobilization of arsenic and other trace elementof health concern in groundwater from the Salı River BasinTucuman Province Argentinardquo Environmental Geochemistryand Health vol 34 no 2 pp 251ndash262 2012
[16] RMOsicka N Agullo C Herrera Ahuad andMC GimenezldquoEvaluacion de las concentraciones de fluoruro y arsenico enlas aguas subterraneas del Domo Central de la provincia delChacordquo Comunicaciones Cientıficas y Tecnologicas Univer-sidad Nacional del Nordeste 2002 httpwwwunneeduarunneviejaWebcytcyt200208-ExactasE-049pdf
[17] C E Fiorentino J D Paoloni M E Sequeira and P ArosteguyldquoThe presence of vanadium in groundwater of southeasternextreme the pampean region Argentina Relationship withother chemical elementsrdquo Journal of Contaminant Hydrologyvol 93 no 1ndash4 pp 122ndash129 2007
[18] P Sprechmann F G Acenaloza C Gaucher A C R Nogueiraand M J Perez ldquoTrasgresion Paranaense paleoestuario deltethys del miocenomedio yo superior en Sudamericardquo in Con-greso Latinoamericano de Geologıa Montevideo-UruguayAbstracts 1 CDRoom pp 10ndash15 Sociedad Latinoamericana deGeologıa 2001
[19] F Larroza and L S Farina ldquoCaracterizacion hidrogeologica delsistema acuıfero Yrenda (SAY) en Paraguay recurso compar-tido con y Boliviardquo in Proceedings of the IV Congreso Argentinode Hidrogeologıa TOMO II Argentinarıo Cuarto CordobaArgentina 2005
[20] E Popolizio P Y Serra and G O Hort ldquoLa clasificaciontaxonomica del Chacordquo Centro de Geociencia Aplicada vol 3no 1 pp 11ndash32 1980
[21] INTA ldquoInstituto Nacional de Tecnologıa AgropecuariardquoAgrometeorologıa httpwwwintagovarsaenzpemeteorolo-giameteorologiahtm
[22] M G Garcıa O Sracek D S Fernandez andM D V HidalgoldquoFactors affecting arsenic concentration in groundwaters fromNorthwestern Chaco-Pampean Plain Argentinardquo Environmen-tal Geology vol 52 no 7 pp 1261ndash1275 2007
[23] US Environmental Protection Agency ( EPA) ldquoArsenic Inor-ganic United States Environmental Protection Agency Inte-grated Risk Information System (IRIS) (CASRN 7440-38-2)rdquo1998 httpwwwepagovirissubst0278htm
12 ISRN Environmental Chemistry
[24] Comision Nacional de Alimentos (CONAL) Acta Nž 93Reunion Ordinaria 3011 y 0112-2011 (Prorroga Art 982 y 983del CAA)
[25] CAA (Codigo Alimentario Argentino) Cap XII Bebidashıdricas agua y agua gasificada In Codigo Alimentario Argen-tino modificatoria del Art 982 (Res 682007 y 1962007) Ley18 284 Buenos Aires Argentina 2007 httpwwwanmatgovarCODIGOACapitulo XII Agua 2007-05pdf
[26] J L Fernandez Turiel G GalindoM A Parada D GimenoMGarcıa-Valles and J Saavedra ldquoEstado actual del conocimientosobre el arsenico en el agua de Argentina y Chile origenmovilidad y transporterdquo inArsenico en Agua Origen movilidady tratamiento II Seminario Hispano-Latinoamericano sobreTemas Actuales de Hidrologıa Subterranea y IV Congreso Hidro-geologico Argentino pp 1ndash22 Rıo Cuarto Argentina 2005
[27] M L Gomez M T Blarasin and D E Martınez ldquoArsenic andfluoride in a loess aquifer in the central area of Argentinardquo Envi-ronmental Geology vol 57 no 1 pp 143ndash155 2009
[28] P L Smedley D G Kinniburgh D M J Macdonald et alldquoArsenic associations in sediments from the loess aquifer of LaPampa Argentinardquo Applied Geochemistry vol 20 no 5 pp989ndash1016 2005
[29] D L Ozsvath ldquoFluoride and environmental health a reviewrdquoReviews in Environmental Science and Biotechnology vol 8 no1 pp 59ndash79 2009
[30] E M Farfan Torres P M Naranjo A Boemo I Lomnicziand L Lorenzo ldquoDistribution of arsenic in groundwater in theChaco Salteno Argentinardquo in Workshop on as Distribution inIbero-America M I Litter Ed CyTED IBEROARSENAbstractBook pp 57ndash60 2006
[31] httpwwwjctoniccomincludemineralsboronhtm[32] M A Halim R K Majumder S A Nessa et al ldquoEvaluation
of processes controlling the geochemical constituents in deepgroundwater in Bangladesh spatial variability on arsenic andboron enrichmentrdquo Journal of HazardousMaterials vol 180 no1ndash3 pp 50ndash62 2010
[33] J BuschmannM Berg C Stengel andM L Sampson ldquoArsenicand manganese contamination of drinking water resources inCambodia coincidence of risk areaswith low relief topographyrdquoEnvironmental Science and Technology vol 41 no 7 pp 2146ndash2152 2007
[34] R A Beckman A S Mildvan and L A Loeb ldquoOn the fidelityof DNA replication manganese mutagenesis in vitrordquo Biochem-istry vol 24 no 21 pp 5810ndash5817 1985
[35] S-H Kim K Kim K-S Ko Y Kim and K-S Lee ldquoCo-con-tamination of arsenic andfluoride in the groundwater of uncon-solidated aquifers under reducing environmentsrdquoChemospherevol 87 no 8 pp 851ndash856 2012
the samples exceeded theWHO guideline value of 15mg Lminus1[5] About 47 of all analyzed samples showed F values above1mg Lminus1 recommended by CAA (Table 4) Similar correla-tions between As and F were also observed in groundwaterfrom neighboring Santiago del Estero [13] Santa Fe [14] andSalta Provinces [30]
In the same way as arsenic the F rich water is character-ized by high concentration of Na+ and low concentration ofCa2+ and Mg2+ (1199032 = 045 009 and 016 resp) Fluoride is ahighly reactive element that combines with other elements incovalent and ionic bonds It is mainly found in alkaline rocksand alkaline soils fluorite being the principal componentGomez et al [27] explain that the processes that could controlthe low relationship between F and Ca2+ and the positiverelationship between F and bicarbonate (1199032 = 024) would bethe balance equation relating calcite and fluorite when bothare in contact with water
As and other trace elements such as V Mo U and minorelements such as B and F are presumed to have their originalsource in volcanic ashes originated from the volcanismin the Andes (5ndash25 in the loess-type sediments of theChaco-Pampean plain) [9] The main components of thesesediments are feldspars quartz volcanic glass shards andminor amounts of muscovite and calcite The compositionof volcanic glass is typically rhyolitic containing a highconcentration of F As V and B among other trace elements[28]
33 Other Trace Elements A series of various trace elementsincluding Ag Al B Ba Be Cd Co Cr Cu Fe Mn MoNi P Pb S Sb Se Si Sr Ti V and Zn were also deter-mined in the studied groundwater The concentrations oftarget elements are summarized in Table 3 Among all 23target analytes concentrations exceeding the WHO recom-mended drinking water limits (in parentheses) were foundfor B (2400120583g Lminus1) Ba (700 120583g Lminus1) Cd (3 120583g Lminus1) and Sb(20120583g Lminus1) Table 4 shows the percentage of groundwatersamples exceeding these WHO and CAA elemental concen-tration guidelines On the other hand concentrations of SnCo Cu Ni S Se Sr V and Zn were very low Silver beryl-lium chrome selenium lead and titanium are not includ inTables 2 and 3 because these elements were never found aboverespective quantification limits
From the samples investigated only one (M45) showedelevated value of barium (1400 120583g Lminus1) than in the WHOdrinking water guideline (700 120583g Lminus1) with an average valueof 122120583g Lminus1 (Table 2)
In small quantities B is essential for healthy bones jointfunction and the metabolism of steroidal hormonesBoron deficiency seems to affect calcium and magnesiummetabolism and affects the composition structure andstrength of bone [31]The concentrations of boron (B) rangedfrom 1560 to 21910 120583g Lminus1 with an average of 4020120583g Lminus1(Table 2) Boron concentration in the 44 (2045) ofthe samples exceeds the WHO and 78 (3545) of thesamples exceeds the CAA standard limits for drinking water(Table 4) The highest concentration of boron was observedin sample M40 which is associated with the largest value
of EC (19371 120583S cmminus1) In general the presence of boron ingroundwater depends on its salinity (represented as EC) suchthat it increases with increasing salinity [32] In this studya positive correlation between EC and boron (1199032 = 064)suggests that boron might be associated with the salinity ofthese samplesHence the salinitymainly reflects the variationof Clminus concentration with a strong linear correlation(1199032 = 091) between EC and Clminus suggesting that the increaseof Clminus concentration contributes to increase in EC valueThehydraulic conductivity salinity type of clay sediments pHand temperature are the crucial factors that determine boronmobility in the groundwater system [32] Boron was stronglycorrelated with Na+ K+ Mg2+ Clminus SO
4
2minus HCO3
minus andAs probably due to their common origin The correlationbetween B and As is often observed in groundwater [1 13]
Our results indicate that approximately 31 of thegroundwater samples tested exceeded the CAA criteria of300 120583g Lminus1 for total Fe in drinking water The highest totalFe concentration (2000120583g Lminus1) appeared in sample M38 Ingeneral Fe concentrationwas low in the studied groundwatersamples only fourteen samples had higher Fe with a meanvalue of 276120583g Lminus1 and median value of 81 120583g Lminus1 On theother hand weaker correlation is observed between Fe andAsin groundwater (1199032 = 017) Moreover almost all groundwa-ter with high Fe concentration (gt300120583g Lminus1) contained totalAs concentration over 10 120583g Lminus1 (Table 3)
The concentration of dissolved Al varied between 600to 17380 120583g Lminus1 with a mean value of 561120583g Lminus1 (Table 2)A 16 (745) exceeded the 200120583g Lminus1 CAA drinking waterguideline However the mean concentration of Al decreasessignificantly down to 178120583g Lminus1 (median 985120583g Lminus1) if theanomalous of sample M24 is excluded Also Aluminumshows no correlation with As (1199032 = minus006)
Manganese exceeded the 100 120583g Lminus1 CAA drinking waterguideline value in 13 (645) of the samples (Tables 3 and4) The highest Mn concentration (3740 120583g Lminus1) was foundin sample M32 However the mean concentration of Mndecreases significantly from 152 to 700 120583g Lminus1 (median500120583g Lminus1) if the anomalous value of this sample is exclud-ed Manganese shows no correlation with As (1199032 = minus007)Mn is known as an essential element for human survivalserves as a catalyst and cofactor in many enzymatic processesinvolved in the synthesis of fatty acids and cholesterol Thechronic ingestion of Mn in drinking water is associated withneurologic damage [33] Moreover manganese is a knownmutagen [34]
Many samples have Fe Al and Mn concentrationsbelow detection limits and most have below CAA guidelinevalue However concentrations are higher in a few samples(Table 2) Smedley et al [1] suggest that at the pH of thegroundwater the high concentrations for these elements traceare most likely due to presence of colloidal particles As thegroundwater are oxidizing solubility of Fe Al andMnoxidesis low and concentrations of dissolved Fe Al and Mn aretherefore mostly low
The processes of dissolution and release from oxides andoxyhydroxides mainly Al Mn and Fe control the presence
8 ISRN Environmental Chemistry
Table3Tracee
lementcom
positionof
grou
ndwater
samples
from
theC
omandanteF
ernand
ezDepartm
entCh
aco
SampleID
As(to
t)F
Al
FeMn
BBa
Mo
SiV
Cd
SrCo
Ni
ZnCu
SP (
tot)
SbQL
500
010
100
100
500
200
100
100
500
100
300
250
100
100
100
100
0025
010
250
M1
500
190
110
600
500
1598
bql
126
bql
830
500
730
bql
bql
bql
bql
110
080
bql
M2
250
050
120
401
bql
310
156
bql
309
450
bql
420
bql
bql
bql
bql
200
030
bql
M3
100
180
900
160
300
875
bql
bql
bql
100
bql
691
bql
bql
300
bql
107
290
bql
M4
150
030
100
bql
bql
206
bql
bql
bql
220
bql
290
bql
bql
bql
bql
700
030
bql
M5
127
074
220
bql
900
811
791
420
227
119bq
l594
bql
bql
410
bql
020
090
bql
M6
580
080
110
bql
bql
297
100
bql
bql
440
bql
498
bql
bql
bql
bql
700
050
bql
M7
240
040
100
bql
bql
275
482
120
bql
430
bql
230
bql
bql
bql
bql
800
030
bql
M8
120
100
100
bql
600
2654
790
bql
2099
900
300
2012
bql
bql
bql
bql
110
080
bql
M9
178
198
130
550
700
1550
101
990
549
163
700
811
bql
bql
bql
630
700
080
900
M10
500
260
800
220
870
15070
bql
160
16570
390
400
4871
bql
bql
bql
bql
725
190
bql
M11
250
224
100
bql
600
1387
bql
140
480
230
bql
641
bql
bql
bql
bql
132
050
bql
M12
110
044
100
bql
194
500
620
bql
114530
bql
334
bql
100
bql
bql
130
060
bql
M13
952
110
110
bql
500
500
269
420
bql
760
400
683
bql
bql
bql
bql
100
030
300
M14
11615
0110
bql
500
665
bql
431
bql
650
500
540
bql
bql
bql
bql
700
070
bql
M15
310
050
102
500
500
2449
402
303
680
570
bql
521
bql
bql
bql
bql
490
060
bql
M16
290
040
130
150
500
255
518
bql
490
110
bql
362
bql
bql
bql
bql
260
030
bql
M17
830
120
100
bql
bql
1782
403
bql
3940
940
300
1427
bql
bql
bql
bql
113
020
300
M18
620
080
700
bql
182
734
bql
bql
2550
280
bql
2510
bql
bql
bql
bql
281
060
bql
M19
100
020
110
bql
500
298
144
bql
bql
300
bql
157
bql
bql
bql
bql
800
050
bql
M20
112
145
100
bql
bql
2316
220
109
4750
112
300
1390
bql
bql
bql
bdl
147
040
bql
M21
700
190
100
bql
254
2470
bql
112
353
280
bql
1361
bql
bql
bql
bql
415
890
bql
M22
100
020
100
bql
292
156
169
bql
bql
bql
bql
860
bql
bql
bql
bql
600
150
bql
M23
360
030
110
bql
bql
630
109
bql
bql
300
bql
225
bql
bql
bql
bql
500
070
900
M24
860
075
17380
310
296
21560
111
bql
1380
120
300
324
bql
bql
321
bql
010
080
bql
M25
770
120
2980
bql
521
6308
bql
bql
1647
220
Bql
bql
bql
100
2831
320
010
250
400
M26
100
340
600
110
bql
1800
150
210
150
198
300
150
bql
bql
bql
bql
006
180
bql
M27
214
420
600
855
bql
6890
bql
213
150
560
300
213
280
bql
670
280
006
110
bql
M28
100
340
600
428
bql
8450
bql
214
150
219
300
150
220
bql
bql
220
006
670
bql
M29
100
060
600
660
bql
6850
bql
208
150
100
300
150
bql
bql
670
bql
006
770
bql
M30
244
090
600
810
330
3050
185
210
150
547
300
150
bql
bql
240
bql
006
130
250
M31
770
340
280
1013
230
7290
bql
210
150
2646
300
322
bql
bql
bql
bql
030
030
bql
M32
700
010
210
286
3740
5080
632
209
150
bql
300
164
640
bql
110
640
020
230
300
M33
174
170
600
734
321
2790
690
210
7540
266
300
150
bql
bql
270
bql
Bql
220
bql
M34
317
030
360
575
240
1970
118
214
150
436
300
150
bql
bql
bql
bql
040
060
bql
M35
1073
030
600
194
bql
6340
301
205
150
1249
300
150
120
bql
490
120
006
030
300
M36
1990
425
600
510
135580
bql
210
150
251
300
288
240
bql
130
bql
006
530
300
M37
200
030
570
606
131290
113
210
150
387
300
203
240
100
160
670
060
050
bql
M38
150
190
600
2000
bql
3710
bql
210
150
380
300
200
950
bql
bql
bql
006
030
300
M39
200
050
600
300
bql
4830
140
210
150
104
300
200
bql
bql
bql
670
006
990
140
ISRN Environmental Chemistry 9
Table3Con
tinued
SampleID
As(to
t)F
Al
FeMn
BBa
Mo
SiV
Cd
SrCo
Ni
ZnCu
SP (
tot)
SbM40
200
050
600
689
bql
21910
bql
210
150
124
300
200
bql
bql
bql
240
006
130
300
M41
150
150
600
988
bql
21580
bql
210
150
176
300
302
bql
bql
bql
bql
006
110
300
M42
130
080
600
426
bql
1970
bql
210
150
345
300
369
180
bql
270
111
006
020
300
M43
150
140
600
700
431
1030
107
210
150
bql
300
bql
550
bql
220
270
006
080
bql
M44
100
120
600
800
bql
2600
289
210
150
191
300
bql
bql
bql
bql
bql
006
480
bql
M45
200
160
600
262
331
240
1400
210
150
350
300
bql
bql
bql
110490
006
230
bql
QLqu
antifi
ctionlim
itbq
lbello
wqu
antifi
catio
nlim
itallcon
centratio
nsaree
xpressed
as120583gLminus1excepted
forF
Sand
Pexpressedas
mgLminus1
10 ISRN Environmental Chemistry
Table 4 Risk-based drinking water criteria and the percentage ofgroundwater samples exceeding these criteria
NA not applicablelowastWHO World Health Organization have not established risk-based drink-ing water criteria for Al Ag Be Bi Co Fe Mn Mo Si Sr Ti V and ZnlowastlowastCAA Codigo Alimentario ArgentinolowastlowastlowastProvisional guideline value
and mobility of As and F in groundwater [1] Kim et al [35]suggested that the cocontamination of As and F observed inoxidizing aquifers in many countries is associated with thedesorption from the Fe-(hydr) oxides by the pH increasesThe correlations between As and F are generally very high inthose aquifers because the As released from Fe-(hydr) oxidesdoes not readily precipitate again in the oxidizing alkalinecondition This is consistent with our observations as manyof the samples show high pH values and moderate coefficientcorrelation value between As and F (1199032 = 050) Alsosolubility of Al minerals may be enhanced by the complex ofdissolved Al with F that is also released from volcanic glasses
Vanadium in groundwater ranged between lt100 (QL)and 2646 120583g Lminus1 The highest V concentration was found insample M31 (Table 2) Vanadium shows a moderated positivecorrelation with As (1199032 = 042) and is likely to be derivedfrom similar mineral sources (secondary Fe and Mn oxides)under the high pH conditions [1] Our results also indicatethat Mo in general appears in low concentrations (Table 3)Molybdenum is weakly correlated with As (1199032 = 020)
Gomez et al [27] suggest that V U B and Mo areenriched in volcanic materials and are mobilized as vanadatemolybdate borate and so forth under oxidizing conditionsAlternatively they are mobilized in alkaline solutions under
conditions of high pH and high HCO3
minus controlled bycarbonate reactions (eg the F may be forming anioniccomplexes with B Fe and Al)
Antimony (Sb) is ubiquity a GroupV of the periodic tableand is similar to As in aspects as chemical behavior andtoxicity to animals [5] The Sb concentrations in studiedsamples exceeded 20120583g Lminus1 WHO and CAA drinking waterguideline values in 45 (245) of the analyzed samples(Tables 3 and 4)
Cadmium reaches a maximum of 70120583g Lminus1 with mostsamples being less than 30 120583g Lminus1 As this element formscationic species in solution its mobilization is not favoredunder the alkaline conditions of the groundwater [1]
The presence of arsenic and heavy metals in the samplescollected from this region of Chaco in Argentina may be dueto local geochemical conditions that facilitate the transfer ofnaturally occurring arsenic from soil and sediment to thewaterThe people in the Comandante FernandezDepartmentmay be overexposed not only toAs but also to B CdMn andF Adverse health effects may appear in coming years Thisproblem is a serious concern for the local population
4 Conclusions
The results of the current study indicate that approximately91 of the groundwater samples used for consumptionby human and livestock from the Comandante FernandezDepartment (Chaco province Argentina) exceed the WHOprovisional guideline value of 10 120583g Lminus1 As recommended asa maximum allowable level in potable water
Evaporation potentiated in arid and semiarid zonefavors the increase of salinity and alkalinity the results is alow quality of the resource but is not conditioning the con-centration of As and F Hence factors other than evaporationsuch as desorption from metal oxides and possibly silicatereaction could be likely controlling As and F mobiliza-tion Furthermore arsenic associated trace elements may beabsorbed on the surface of iron and aluminum oxides andoxyhydroxides (hematite goethite Fe(OH)
3
and gibbsite)limiting the mobility of trace elements Groundwater withhigh pH values and high concentration of bicarbonate wouldfacilitate the dissolution of volcanic glass thus trace elementsmay enter groundwater cycles forming anionic complexes inalkaline solutions and acquiring great mobility
The hydrochemical trace in the region is characterizedby high salinity and high As and F concentrations whichis related to volcanism and hydrothermal activity from theAndes This association is often linked to presence of BCd Mo Mn and V indicating their common origin in thevolcanic glasses
Due to high As concentrations found in groundwaterserious health risk must be considered The population inthe area may be exposed to the chronic toxicological effectsof hydro arsenicism and fluorosis increasing the risks ofcontracting other diseases derived from them Since thegroundwater studied here constitutes the principal source ofdrinking water in the zone mitigation efforts should not belimited to As health risks from other toxic elements presentin drinking water must also be addressed in this region
ISRN Environmental Chemistry 11
Conflict of Interest
The authors declare that there is no conflict of interestsregarding the publication of this paper Its publication isapproved by all authors and tacitly or explicitly by the respon-sible authorities where the work was carried out and that ifaccepted it will not be published elsewhere in the same formin English or in any other language including electronicallywithout the written consent of the copyright-holder
Acknowledgments
This work was supported with funds from PI 3600005 Uni-versidad Nacional del Chaco Austral (UNCAus) Patricia SBlanes thanks the National Academy of Exact Physic andNatural Sciences for granting a PhD fellowship
References
[1] P L Smedley H B Nicolli DM JMacdonald A J Barros andJ O Tullio ldquoHydrogeochemistry of arsenic and other inorganicconstituents in groundwaters from La Pampa ArgentinardquoApplied Geochemistry vol 17 no 3 pp 259ndash284 2002
[2] S Muhammad M T Shah and S Khan ldquoHealth risk assess-ment of heavy metals and their source apportionment in drink-ingwater of Kohistan region northern PakistanrdquoMicrochemicalJournal vol 98 no 2 pp 334ndash343 2011
[3] S S Farıas V A Casa C Vazquez L Ferpozzi G N Pucci andI M Cohen ldquoNatural contamination with arsenic and othertrace elements in ground waters of Argentine Pampean PlainrdquoScience of the Total Environment vol 309 no 1ndash3 pp 187ndash1992003
[4] L Jarup ldquoHazards of heavy metal contaminationrdquo British Med-ical Bulletin vol 68 pp 167ndash182 2003
[5] World Health Organization (WHO) ldquoRecommendationsrdquo inGuidelines for Drinking Water Quality vol 1 Geneva Switzer-land 4th edition 2011
[6] C Hopenhayn ldquoArsenic in drinking water impact on humanhealthrdquo Elements vol 2 no 2 pp 103ndash107 2006
[7] S H Lamm and M B Kruse ldquoArsenic ingestion and bladdercancermortalitymdashwhat do the dose-response relationships sug-gest aboutmechanismrdquoHumanandEcological RiskAssessmentvol 11 no 2 pp 433ndash450 2005
[8] C-HWang C K Hsiao C-L Chen et al ldquoA review of the epi-demiologic literature on the role of environmental arsenicexposure and cardiovascular diseasesrdquo Toxicology and AppliedPharmacology vol 222 no 3 pp 315ndash326 2007
[9] J Bundschuh M I Litter F Parvez et al ldquoOne century ofarsenic exposure in Latin America a review of history andoccurrence from 14 countriesrdquo Science of the Total Environmentvol 429 pp 2ndash35 2012
[10] M T Alarcon-Herrera J Bundschuh B Nath et al ldquoCo-occurrence of arsenic and fluoride in groundwater of semi-aridregions in Latin America genesis mobility and remediationrdquoJournal of Hazardous Materials 2012
[11] E E Buchhamer P S Blanes RM Osicka andM C GimenezldquoEnvironmental risk assessment of arsenic and fluoride in thechaco province argentina research advancesrdquo Journal of Toxi-cology and Environmental Health A vol 75 no 22-23 pp 1437ndash1450 2012
[12] A Cabrera M Blarasin E Matteoda G Villalva and M LGomez ldquoComposicion quımica del agua subterranea en el surde Cordoba lınea de base hidroquımica o fondo natural enreferencia a arsenico y fluorrdquo in Aguas Superficiales y Sub-terraneas en el sur ae Cordoba Una Perspectiva GeoambientalM Blarasin S Degiovanni A Cabera and M Villegas Edspp 81ndash90 Universidad Nacional de Rıo Cuarto Rıo CuartoArgentina 2005
[13] P Bhattacharya M Claesson J Bundschuh et al ldquoDistributionand mobility of arsenic in the Rıo Dulce alluvial aquifers inSantiago del Estero Province Argentinardquo Science of the TotalEnvironment vol 358 no 1ndash3 pp 97ndash120 2006
[14] B Nicolli O C Tujchneider M C Paris M Blanco and A JBarros ldquoMovilidad del arsenico y oligoelementos asociados enaguas subterraneas del centro-norte de la provincia de Santa FeArgentinardquo in Proceedings of the Presencia de Fluor y Arsenicoen Aguas Subterraneas VI Congreso Hidrogeologico ArgentinoG Galindo J L Fernandez Turiel and A Storniolo Eds pp81ndash90 Santa Rosa La Pampa Argentina 2009
[15] H B Nicolli A Tineo J W Garcıa C M Falcon and PL Smedley ldquoMobilization of arsenic and other trace elementof health concern in groundwater from the Salı River BasinTucuman Province Argentinardquo Environmental Geochemistryand Health vol 34 no 2 pp 251ndash262 2012
[16] RMOsicka N Agullo C Herrera Ahuad andMC GimenezldquoEvaluacion de las concentraciones de fluoruro y arsenico enlas aguas subterraneas del Domo Central de la provincia delChacordquo Comunicaciones Cientıficas y Tecnologicas Univer-sidad Nacional del Nordeste 2002 httpwwwunneeduarunneviejaWebcytcyt200208-ExactasE-049pdf
[17] C E Fiorentino J D Paoloni M E Sequeira and P ArosteguyldquoThe presence of vanadium in groundwater of southeasternextreme the pampean region Argentina Relationship withother chemical elementsrdquo Journal of Contaminant Hydrologyvol 93 no 1ndash4 pp 122ndash129 2007
[18] P Sprechmann F G Acenaloza C Gaucher A C R Nogueiraand M J Perez ldquoTrasgresion Paranaense paleoestuario deltethys del miocenomedio yo superior en Sudamericardquo in Con-greso Latinoamericano de Geologıa Montevideo-UruguayAbstracts 1 CDRoom pp 10ndash15 Sociedad Latinoamericana deGeologıa 2001
[19] F Larroza and L S Farina ldquoCaracterizacion hidrogeologica delsistema acuıfero Yrenda (SAY) en Paraguay recurso compar-tido con y Boliviardquo in Proceedings of the IV Congreso Argentinode Hidrogeologıa TOMO II Argentinarıo Cuarto CordobaArgentina 2005
[20] E Popolizio P Y Serra and G O Hort ldquoLa clasificaciontaxonomica del Chacordquo Centro de Geociencia Aplicada vol 3no 1 pp 11ndash32 1980
[21] INTA ldquoInstituto Nacional de Tecnologıa AgropecuariardquoAgrometeorologıa httpwwwintagovarsaenzpemeteorolo-giameteorologiahtm
[22] M G Garcıa O Sracek D S Fernandez andM D V HidalgoldquoFactors affecting arsenic concentration in groundwaters fromNorthwestern Chaco-Pampean Plain Argentinardquo Environmen-tal Geology vol 52 no 7 pp 1261ndash1275 2007
[23] US Environmental Protection Agency ( EPA) ldquoArsenic Inor-ganic United States Environmental Protection Agency Inte-grated Risk Information System (IRIS) (CASRN 7440-38-2)rdquo1998 httpwwwepagovirissubst0278htm
12 ISRN Environmental Chemistry
[24] Comision Nacional de Alimentos (CONAL) Acta Nž 93Reunion Ordinaria 3011 y 0112-2011 (Prorroga Art 982 y 983del CAA)
[25] CAA (Codigo Alimentario Argentino) Cap XII Bebidashıdricas agua y agua gasificada In Codigo Alimentario Argen-tino modificatoria del Art 982 (Res 682007 y 1962007) Ley18 284 Buenos Aires Argentina 2007 httpwwwanmatgovarCODIGOACapitulo XII Agua 2007-05pdf
[26] J L Fernandez Turiel G GalindoM A Parada D GimenoMGarcıa-Valles and J Saavedra ldquoEstado actual del conocimientosobre el arsenico en el agua de Argentina y Chile origenmovilidad y transporterdquo inArsenico en Agua Origen movilidady tratamiento II Seminario Hispano-Latinoamericano sobreTemas Actuales de Hidrologıa Subterranea y IV Congreso Hidro-geologico Argentino pp 1ndash22 Rıo Cuarto Argentina 2005
[27] M L Gomez M T Blarasin and D E Martınez ldquoArsenic andfluoride in a loess aquifer in the central area of Argentinardquo Envi-ronmental Geology vol 57 no 1 pp 143ndash155 2009
[28] P L Smedley D G Kinniburgh D M J Macdonald et alldquoArsenic associations in sediments from the loess aquifer of LaPampa Argentinardquo Applied Geochemistry vol 20 no 5 pp989ndash1016 2005
[29] D L Ozsvath ldquoFluoride and environmental health a reviewrdquoReviews in Environmental Science and Biotechnology vol 8 no1 pp 59ndash79 2009
[30] E M Farfan Torres P M Naranjo A Boemo I Lomnicziand L Lorenzo ldquoDistribution of arsenic in groundwater in theChaco Salteno Argentinardquo in Workshop on as Distribution inIbero-America M I Litter Ed CyTED IBEROARSENAbstractBook pp 57ndash60 2006
[31] httpwwwjctoniccomincludemineralsboronhtm[32] M A Halim R K Majumder S A Nessa et al ldquoEvaluation
of processes controlling the geochemical constituents in deepgroundwater in Bangladesh spatial variability on arsenic andboron enrichmentrdquo Journal of HazardousMaterials vol 180 no1ndash3 pp 50ndash62 2010
[33] J BuschmannM Berg C Stengel andM L Sampson ldquoArsenicand manganese contamination of drinking water resources inCambodia coincidence of risk areaswith low relief topographyrdquoEnvironmental Science and Technology vol 41 no 7 pp 2146ndash2152 2007
[34] R A Beckman A S Mildvan and L A Loeb ldquoOn the fidelityof DNA replication manganese mutagenesis in vitrordquo Biochem-istry vol 24 no 21 pp 5810ndash5817 1985
[35] S-H Kim K Kim K-S Ko Y Kim and K-S Lee ldquoCo-con-tamination of arsenic andfluoride in the groundwater of uncon-solidated aquifers under reducing environmentsrdquoChemospherevol 87 no 8 pp 851ndash856 2012
NA not applicablelowastWHO World Health Organization have not established risk-based drink-ing water criteria for Al Ag Be Bi Co Fe Mn Mo Si Sr Ti V and ZnlowastlowastCAA Codigo Alimentario ArgentinolowastlowastlowastProvisional guideline value
and mobility of As and F in groundwater [1] Kim et al [35]suggested that the cocontamination of As and F observed inoxidizing aquifers in many countries is associated with thedesorption from the Fe-(hydr) oxides by the pH increasesThe correlations between As and F are generally very high inthose aquifers because the As released from Fe-(hydr) oxidesdoes not readily precipitate again in the oxidizing alkalinecondition This is consistent with our observations as manyof the samples show high pH values and moderate coefficientcorrelation value between As and F (1199032 = 050) Alsosolubility of Al minerals may be enhanced by the complex ofdissolved Al with F that is also released from volcanic glasses
Vanadium in groundwater ranged between lt100 (QL)and 2646 120583g Lminus1 The highest V concentration was found insample M31 (Table 2) Vanadium shows a moderated positivecorrelation with As (1199032 = 042) and is likely to be derivedfrom similar mineral sources (secondary Fe and Mn oxides)under the high pH conditions [1] Our results also indicatethat Mo in general appears in low concentrations (Table 3)Molybdenum is weakly correlated with As (1199032 = 020)
Gomez et al [27] suggest that V U B and Mo areenriched in volcanic materials and are mobilized as vanadatemolybdate borate and so forth under oxidizing conditionsAlternatively they are mobilized in alkaline solutions under
conditions of high pH and high HCO3
minus controlled bycarbonate reactions (eg the F may be forming anioniccomplexes with B Fe and Al)
Antimony (Sb) is ubiquity a GroupV of the periodic tableand is similar to As in aspects as chemical behavior andtoxicity to animals [5] The Sb concentrations in studiedsamples exceeded 20120583g Lminus1 WHO and CAA drinking waterguideline values in 45 (245) of the analyzed samples(Tables 3 and 4)
Cadmium reaches a maximum of 70120583g Lminus1 with mostsamples being less than 30 120583g Lminus1 As this element formscationic species in solution its mobilization is not favoredunder the alkaline conditions of the groundwater [1]
The presence of arsenic and heavy metals in the samplescollected from this region of Chaco in Argentina may be dueto local geochemical conditions that facilitate the transfer ofnaturally occurring arsenic from soil and sediment to thewaterThe people in the Comandante FernandezDepartmentmay be overexposed not only toAs but also to B CdMn andF Adverse health effects may appear in coming years Thisproblem is a serious concern for the local population
4 Conclusions
The results of the current study indicate that approximately91 of the groundwater samples used for consumptionby human and livestock from the Comandante FernandezDepartment (Chaco province Argentina) exceed the WHOprovisional guideline value of 10 120583g Lminus1 As recommended asa maximum allowable level in potable water
Evaporation potentiated in arid and semiarid zonefavors the increase of salinity and alkalinity the results is alow quality of the resource but is not conditioning the con-centration of As and F Hence factors other than evaporationsuch as desorption from metal oxides and possibly silicatereaction could be likely controlling As and F mobiliza-tion Furthermore arsenic associated trace elements may beabsorbed on the surface of iron and aluminum oxides andoxyhydroxides (hematite goethite Fe(OH)
3
and gibbsite)limiting the mobility of trace elements Groundwater withhigh pH values and high concentration of bicarbonate wouldfacilitate the dissolution of volcanic glass thus trace elementsmay enter groundwater cycles forming anionic complexes inalkaline solutions and acquiring great mobility
The hydrochemical trace in the region is characterizedby high salinity and high As and F concentrations whichis related to volcanism and hydrothermal activity from theAndes This association is often linked to presence of BCd Mo Mn and V indicating their common origin in thevolcanic glasses
Due to high As concentrations found in groundwaterserious health risk must be considered The population inthe area may be exposed to the chronic toxicological effectsof hydro arsenicism and fluorosis increasing the risks ofcontracting other diseases derived from them Since thegroundwater studied here constitutes the principal source ofdrinking water in the zone mitigation efforts should not belimited to As health risks from other toxic elements presentin drinking water must also be addressed in this region
ISRN Environmental Chemistry 11
Conflict of Interest
The authors declare that there is no conflict of interestsregarding the publication of this paper Its publication isapproved by all authors and tacitly or explicitly by the respon-sible authorities where the work was carried out and that ifaccepted it will not be published elsewhere in the same formin English or in any other language including electronicallywithout the written consent of the copyright-holder
Acknowledgments
This work was supported with funds from PI 3600005 Uni-versidad Nacional del Chaco Austral (UNCAus) Patricia SBlanes thanks the National Academy of Exact Physic andNatural Sciences for granting a PhD fellowship
References
[1] P L Smedley H B Nicolli DM JMacdonald A J Barros andJ O Tullio ldquoHydrogeochemistry of arsenic and other inorganicconstituents in groundwaters from La Pampa ArgentinardquoApplied Geochemistry vol 17 no 3 pp 259ndash284 2002
[2] S Muhammad M T Shah and S Khan ldquoHealth risk assess-ment of heavy metals and their source apportionment in drink-ingwater of Kohistan region northern PakistanrdquoMicrochemicalJournal vol 98 no 2 pp 334ndash343 2011
[3] S S Farıas V A Casa C Vazquez L Ferpozzi G N Pucci andI M Cohen ldquoNatural contamination with arsenic and othertrace elements in ground waters of Argentine Pampean PlainrdquoScience of the Total Environment vol 309 no 1ndash3 pp 187ndash1992003
[4] L Jarup ldquoHazards of heavy metal contaminationrdquo British Med-ical Bulletin vol 68 pp 167ndash182 2003
[5] World Health Organization (WHO) ldquoRecommendationsrdquo inGuidelines for Drinking Water Quality vol 1 Geneva Switzer-land 4th edition 2011
[6] C Hopenhayn ldquoArsenic in drinking water impact on humanhealthrdquo Elements vol 2 no 2 pp 103ndash107 2006
[7] S H Lamm and M B Kruse ldquoArsenic ingestion and bladdercancermortalitymdashwhat do the dose-response relationships sug-gest aboutmechanismrdquoHumanandEcological RiskAssessmentvol 11 no 2 pp 433ndash450 2005
[8] C-HWang C K Hsiao C-L Chen et al ldquoA review of the epi-demiologic literature on the role of environmental arsenicexposure and cardiovascular diseasesrdquo Toxicology and AppliedPharmacology vol 222 no 3 pp 315ndash326 2007
[9] J Bundschuh M I Litter F Parvez et al ldquoOne century ofarsenic exposure in Latin America a review of history andoccurrence from 14 countriesrdquo Science of the Total Environmentvol 429 pp 2ndash35 2012
[10] M T Alarcon-Herrera J Bundschuh B Nath et al ldquoCo-occurrence of arsenic and fluoride in groundwater of semi-aridregions in Latin America genesis mobility and remediationrdquoJournal of Hazardous Materials 2012
[11] E E Buchhamer P S Blanes RM Osicka andM C GimenezldquoEnvironmental risk assessment of arsenic and fluoride in thechaco province argentina research advancesrdquo Journal of Toxi-cology and Environmental Health A vol 75 no 22-23 pp 1437ndash1450 2012
[12] A Cabrera M Blarasin E Matteoda G Villalva and M LGomez ldquoComposicion quımica del agua subterranea en el surde Cordoba lınea de base hidroquımica o fondo natural enreferencia a arsenico y fluorrdquo in Aguas Superficiales y Sub-terraneas en el sur ae Cordoba Una Perspectiva GeoambientalM Blarasin S Degiovanni A Cabera and M Villegas Edspp 81ndash90 Universidad Nacional de Rıo Cuarto Rıo CuartoArgentina 2005
[13] P Bhattacharya M Claesson J Bundschuh et al ldquoDistributionand mobility of arsenic in the Rıo Dulce alluvial aquifers inSantiago del Estero Province Argentinardquo Science of the TotalEnvironment vol 358 no 1ndash3 pp 97ndash120 2006
[14] B Nicolli O C Tujchneider M C Paris M Blanco and A JBarros ldquoMovilidad del arsenico y oligoelementos asociados enaguas subterraneas del centro-norte de la provincia de Santa FeArgentinardquo in Proceedings of the Presencia de Fluor y Arsenicoen Aguas Subterraneas VI Congreso Hidrogeologico ArgentinoG Galindo J L Fernandez Turiel and A Storniolo Eds pp81ndash90 Santa Rosa La Pampa Argentina 2009
[15] H B Nicolli A Tineo J W Garcıa C M Falcon and PL Smedley ldquoMobilization of arsenic and other trace elementof health concern in groundwater from the Salı River BasinTucuman Province Argentinardquo Environmental Geochemistryand Health vol 34 no 2 pp 251ndash262 2012
[16] RMOsicka N Agullo C Herrera Ahuad andMC GimenezldquoEvaluacion de las concentraciones de fluoruro y arsenico enlas aguas subterraneas del Domo Central de la provincia delChacordquo Comunicaciones Cientıficas y Tecnologicas Univer-sidad Nacional del Nordeste 2002 httpwwwunneeduarunneviejaWebcytcyt200208-ExactasE-049pdf
[17] C E Fiorentino J D Paoloni M E Sequeira and P ArosteguyldquoThe presence of vanadium in groundwater of southeasternextreme the pampean region Argentina Relationship withother chemical elementsrdquo Journal of Contaminant Hydrologyvol 93 no 1ndash4 pp 122ndash129 2007
[18] P Sprechmann F G Acenaloza C Gaucher A C R Nogueiraand M J Perez ldquoTrasgresion Paranaense paleoestuario deltethys del miocenomedio yo superior en Sudamericardquo in Con-greso Latinoamericano de Geologıa Montevideo-UruguayAbstracts 1 CDRoom pp 10ndash15 Sociedad Latinoamericana deGeologıa 2001
[19] F Larroza and L S Farina ldquoCaracterizacion hidrogeologica delsistema acuıfero Yrenda (SAY) en Paraguay recurso compar-tido con y Boliviardquo in Proceedings of the IV Congreso Argentinode Hidrogeologıa TOMO II Argentinarıo Cuarto CordobaArgentina 2005
[20] E Popolizio P Y Serra and G O Hort ldquoLa clasificaciontaxonomica del Chacordquo Centro de Geociencia Aplicada vol 3no 1 pp 11ndash32 1980
[21] INTA ldquoInstituto Nacional de Tecnologıa AgropecuariardquoAgrometeorologıa httpwwwintagovarsaenzpemeteorolo-giameteorologiahtm
[22] M G Garcıa O Sracek D S Fernandez andM D V HidalgoldquoFactors affecting arsenic concentration in groundwaters fromNorthwestern Chaco-Pampean Plain Argentinardquo Environmen-tal Geology vol 52 no 7 pp 1261ndash1275 2007
[23] US Environmental Protection Agency ( EPA) ldquoArsenic Inor-ganic United States Environmental Protection Agency Inte-grated Risk Information System (IRIS) (CASRN 7440-38-2)rdquo1998 httpwwwepagovirissubst0278htm
12 ISRN Environmental Chemistry
[24] Comision Nacional de Alimentos (CONAL) Acta Nž 93Reunion Ordinaria 3011 y 0112-2011 (Prorroga Art 982 y 983del CAA)
[25] CAA (Codigo Alimentario Argentino) Cap XII Bebidashıdricas agua y agua gasificada In Codigo Alimentario Argen-tino modificatoria del Art 982 (Res 682007 y 1962007) Ley18 284 Buenos Aires Argentina 2007 httpwwwanmatgovarCODIGOACapitulo XII Agua 2007-05pdf
[26] J L Fernandez Turiel G GalindoM A Parada D GimenoMGarcıa-Valles and J Saavedra ldquoEstado actual del conocimientosobre el arsenico en el agua de Argentina y Chile origenmovilidad y transporterdquo inArsenico en Agua Origen movilidady tratamiento II Seminario Hispano-Latinoamericano sobreTemas Actuales de Hidrologıa Subterranea y IV Congreso Hidro-geologico Argentino pp 1ndash22 Rıo Cuarto Argentina 2005
[27] M L Gomez M T Blarasin and D E Martınez ldquoArsenic andfluoride in a loess aquifer in the central area of Argentinardquo Envi-ronmental Geology vol 57 no 1 pp 143ndash155 2009
[28] P L Smedley D G Kinniburgh D M J Macdonald et alldquoArsenic associations in sediments from the loess aquifer of LaPampa Argentinardquo Applied Geochemistry vol 20 no 5 pp989ndash1016 2005
[29] D L Ozsvath ldquoFluoride and environmental health a reviewrdquoReviews in Environmental Science and Biotechnology vol 8 no1 pp 59ndash79 2009
[30] E M Farfan Torres P M Naranjo A Boemo I Lomnicziand L Lorenzo ldquoDistribution of arsenic in groundwater in theChaco Salteno Argentinardquo in Workshop on as Distribution inIbero-America M I Litter Ed CyTED IBEROARSENAbstractBook pp 57ndash60 2006
[31] httpwwwjctoniccomincludemineralsboronhtm[32] M A Halim R K Majumder S A Nessa et al ldquoEvaluation
of processes controlling the geochemical constituents in deepgroundwater in Bangladesh spatial variability on arsenic andboron enrichmentrdquo Journal of HazardousMaterials vol 180 no1ndash3 pp 50ndash62 2010
[33] J BuschmannM Berg C Stengel andM L Sampson ldquoArsenicand manganese contamination of drinking water resources inCambodia coincidence of risk areaswith low relief topographyrdquoEnvironmental Science and Technology vol 41 no 7 pp 2146ndash2152 2007
[34] R A Beckman A S Mildvan and L A Loeb ldquoOn the fidelityof DNA replication manganese mutagenesis in vitrordquo Biochem-istry vol 24 no 21 pp 5810ndash5817 1985
[35] S-H Kim K Kim K-S Ko Y Kim and K-S Lee ldquoCo-con-tamination of arsenic andfluoride in the groundwater of uncon-solidated aquifers under reducing environmentsrdquoChemospherevol 87 no 8 pp 851ndash856 2012
NA not applicablelowastWHO World Health Organization have not established risk-based drink-ing water criteria for Al Ag Be Bi Co Fe Mn Mo Si Sr Ti V and ZnlowastlowastCAA Codigo Alimentario ArgentinolowastlowastlowastProvisional guideline value
and mobility of As and F in groundwater [1] Kim et al [35]suggested that the cocontamination of As and F observed inoxidizing aquifers in many countries is associated with thedesorption from the Fe-(hydr) oxides by the pH increasesThe correlations between As and F are generally very high inthose aquifers because the As released from Fe-(hydr) oxidesdoes not readily precipitate again in the oxidizing alkalinecondition This is consistent with our observations as manyof the samples show high pH values and moderate coefficientcorrelation value between As and F (1199032 = 050) Alsosolubility of Al minerals may be enhanced by the complex ofdissolved Al with F that is also released from volcanic glasses
Vanadium in groundwater ranged between lt100 (QL)and 2646 120583g Lminus1 The highest V concentration was found insample M31 (Table 2) Vanadium shows a moderated positivecorrelation with As (1199032 = 042) and is likely to be derivedfrom similar mineral sources (secondary Fe and Mn oxides)under the high pH conditions [1] Our results also indicatethat Mo in general appears in low concentrations (Table 3)Molybdenum is weakly correlated with As (1199032 = 020)
Gomez et al [27] suggest that V U B and Mo areenriched in volcanic materials and are mobilized as vanadatemolybdate borate and so forth under oxidizing conditionsAlternatively they are mobilized in alkaline solutions under
conditions of high pH and high HCO3
minus controlled bycarbonate reactions (eg the F may be forming anioniccomplexes with B Fe and Al)
Antimony (Sb) is ubiquity a GroupV of the periodic tableand is similar to As in aspects as chemical behavior andtoxicity to animals [5] The Sb concentrations in studiedsamples exceeded 20120583g Lminus1 WHO and CAA drinking waterguideline values in 45 (245) of the analyzed samples(Tables 3 and 4)
Cadmium reaches a maximum of 70120583g Lminus1 with mostsamples being less than 30 120583g Lminus1 As this element formscationic species in solution its mobilization is not favoredunder the alkaline conditions of the groundwater [1]
The presence of arsenic and heavy metals in the samplescollected from this region of Chaco in Argentina may be dueto local geochemical conditions that facilitate the transfer ofnaturally occurring arsenic from soil and sediment to thewaterThe people in the Comandante FernandezDepartmentmay be overexposed not only toAs but also to B CdMn andF Adverse health effects may appear in coming years Thisproblem is a serious concern for the local population
4 Conclusions
The results of the current study indicate that approximately91 of the groundwater samples used for consumptionby human and livestock from the Comandante FernandezDepartment (Chaco province Argentina) exceed the WHOprovisional guideline value of 10 120583g Lminus1 As recommended asa maximum allowable level in potable water
Evaporation potentiated in arid and semiarid zonefavors the increase of salinity and alkalinity the results is alow quality of the resource but is not conditioning the con-centration of As and F Hence factors other than evaporationsuch as desorption from metal oxides and possibly silicatereaction could be likely controlling As and F mobiliza-tion Furthermore arsenic associated trace elements may beabsorbed on the surface of iron and aluminum oxides andoxyhydroxides (hematite goethite Fe(OH)
3
and gibbsite)limiting the mobility of trace elements Groundwater withhigh pH values and high concentration of bicarbonate wouldfacilitate the dissolution of volcanic glass thus trace elementsmay enter groundwater cycles forming anionic complexes inalkaline solutions and acquiring great mobility
The hydrochemical trace in the region is characterizedby high salinity and high As and F concentrations whichis related to volcanism and hydrothermal activity from theAndes This association is often linked to presence of BCd Mo Mn and V indicating their common origin in thevolcanic glasses
Due to high As concentrations found in groundwaterserious health risk must be considered The population inthe area may be exposed to the chronic toxicological effectsof hydro arsenicism and fluorosis increasing the risks ofcontracting other diseases derived from them Since thegroundwater studied here constitutes the principal source ofdrinking water in the zone mitigation efforts should not belimited to As health risks from other toxic elements presentin drinking water must also be addressed in this region
ISRN Environmental Chemistry 11
Conflict of Interest
The authors declare that there is no conflict of interestsregarding the publication of this paper Its publication isapproved by all authors and tacitly or explicitly by the respon-sible authorities where the work was carried out and that ifaccepted it will not be published elsewhere in the same formin English or in any other language including electronicallywithout the written consent of the copyright-holder
Acknowledgments
This work was supported with funds from PI 3600005 Uni-versidad Nacional del Chaco Austral (UNCAus) Patricia SBlanes thanks the National Academy of Exact Physic andNatural Sciences for granting a PhD fellowship
References
[1] P L Smedley H B Nicolli DM JMacdonald A J Barros andJ O Tullio ldquoHydrogeochemistry of arsenic and other inorganicconstituents in groundwaters from La Pampa ArgentinardquoApplied Geochemistry vol 17 no 3 pp 259ndash284 2002
[2] S Muhammad M T Shah and S Khan ldquoHealth risk assess-ment of heavy metals and their source apportionment in drink-ingwater of Kohistan region northern PakistanrdquoMicrochemicalJournal vol 98 no 2 pp 334ndash343 2011
[3] S S Farıas V A Casa C Vazquez L Ferpozzi G N Pucci andI M Cohen ldquoNatural contamination with arsenic and othertrace elements in ground waters of Argentine Pampean PlainrdquoScience of the Total Environment vol 309 no 1ndash3 pp 187ndash1992003
[4] L Jarup ldquoHazards of heavy metal contaminationrdquo British Med-ical Bulletin vol 68 pp 167ndash182 2003
[5] World Health Organization (WHO) ldquoRecommendationsrdquo inGuidelines for Drinking Water Quality vol 1 Geneva Switzer-land 4th edition 2011
[6] C Hopenhayn ldquoArsenic in drinking water impact on humanhealthrdquo Elements vol 2 no 2 pp 103ndash107 2006
[7] S H Lamm and M B Kruse ldquoArsenic ingestion and bladdercancermortalitymdashwhat do the dose-response relationships sug-gest aboutmechanismrdquoHumanandEcological RiskAssessmentvol 11 no 2 pp 433ndash450 2005
[8] C-HWang C K Hsiao C-L Chen et al ldquoA review of the epi-demiologic literature on the role of environmental arsenicexposure and cardiovascular diseasesrdquo Toxicology and AppliedPharmacology vol 222 no 3 pp 315ndash326 2007
[9] J Bundschuh M I Litter F Parvez et al ldquoOne century ofarsenic exposure in Latin America a review of history andoccurrence from 14 countriesrdquo Science of the Total Environmentvol 429 pp 2ndash35 2012
[10] M T Alarcon-Herrera J Bundschuh B Nath et al ldquoCo-occurrence of arsenic and fluoride in groundwater of semi-aridregions in Latin America genesis mobility and remediationrdquoJournal of Hazardous Materials 2012
[11] E E Buchhamer P S Blanes RM Osicka andM C GimenezldquoEnvironmental risk assessment of arsenic and fluoride in thechaco province argentina research advancesrdquo Journal of Toxi-cology and Environmental Health A vol 75 no 22-23 pp 1437ndash1450 2012
[12] A Cabrera M Blarasin E Matteoda G Villalva and M LGomez ldquoComposicion quımica del agua subterranea en el surde Cordoba lınea de base hidroquımica o fondo natural enreferencia a arsenico y fluorrdquo in Aguas Superficiales y Sub-terraneas en el sur ae Cordoba Una Perspectiva GeoambientalM Blarasin S Degiovanni A Cabera and M Villegas Edspp 81ndash90 Universidad Nacional de Rıo Cuarto Rıo CuartoArgentina 2005
[13] P Bhattacharya M Claesson J Bundschuh et al ldquoDistributionand mobility of arsenic in the Rıo Dulce alluvial aquifers inSantiago del Estero Province Argentinardquo Science of the TotalEnvironment vol 358 no 1ndash3 pp 97ndash120 2006
[14] B Nicolli O C Tujchneider M C Paris M Blanco and A JBarros ldquoMovilidad del arsenico y oligoelementos asociados enaguas subterraneas del centro-norte de la provincia de Santa FeArgentinardquo in Proceedings of the Presencia de Fluor y Arsenicoen Aguas Subterraneas VI Congreso Hidrogeologico ArgentinoG Galindo J L Fernandez Turiel and A Storniolo Eds pp81ndash90 Santa Rosa La Pampa Argentina 2009
[15] H B Nicolli A Tineo J W Garcıa C M Falcon and PL Smedley ldquoMobilization of arsenic and other trace elementof health concern in groundwater from the Salı River BasinTucuman Province Argentinardquo Environmental Geochemistryand Health vol 34 no 2 pp 251ndash262 2012
[16] RMOsicka N Agullo C Herrera Ahuad andMC GimenezldquoEvaluacion de las concentraciones de fluoruro y arsenico enlas aguas subterraneas del Domo Central de la provincia delChacordquo Comunicaciones Cientıficas y Tecnologicas Univer-sidad Nacional del Nordeste 2002 httpwwwunneeduarunneviejaWebcytcyt200208-ExactasE-049pdf
[17] C E Fiorentino J D Paoloni M E Sequeira and P ArosteguyldquoThe presence of vanadium in groundwater of southeasternextreme the pampean region Argentina Relationship withother chemical elementsrdquo Journal of Contaminant Hydrologyvol 93 no 1ndash4 pp 122ndash129 2007
[18] P Sprechmann F G Acenaloza C Gaucher A C R Nogueiraand M J Perez ldquoTrasgresion Paranaense paleoestuario deltethys del miocenomedio yo superior en Sudamericardquo in Con-greso Latinoamericano de Geologıa Montevideo-UruguayAbstracts 1 CDRoom pp 10ndash15 Sociedad Latinoamericana deGeologıa 2001
[19] F Larroza and L S Farina ldquoCaracterizacion hidrogeologica delsistema acuıfero Yrenda (SAY) en Paraguay recurso compar-tido con y Boliviardquo in Proceedings of the IV Congreso Argentinode Hidrogeologıa TOMO II Argentinarıo Cuarto CordobaArgentina 2005
[20] E Popolizio P Y Serra and G O Hort ldquoLa clasificaciontaxonomica del Chacordquo Centro de Geociencia Aplicada vol 3no 1 pp 11ndash32 1980
[21] INTA ldquoInstituto Nacional de Tecnologıa AgropecuariardquoAgrometeorologıa httpwwwintagovarsaenzpemeteorolo-giameteorologiahtm
[22] M G Garcıa O Sracek D S Fernandez andM D V HidalgoldquoFactors affecting arsenic concentration in groundwaters fromNorthwestern Chaco-Pampean Plain Argentinardquo Environmen-tal Geology vol 52 no 7 pp 1261ndash1275 2007
[23] US Environmental Protection Agency ( EPA) ldquoArsenic Inor-ganic United States Environmental Protection Agency Inte-grated Risk Information System (IRIS) (CASRN 7440-38-2)rdquo1998 httpwwwepagovirissubst0278htm
12 ISRN Environmental Chemistry
[24] Comision Nacional de Alimentos (CONAL) Acta Nž 93Reunion Ordinaria 3011 y 0112-2011 (Prorroga Art 982 y 983del CAA)
[25] CAA (Codigo Alimentario Argentino) Cap XII Bebidashıdricas agua y agua gasificada In Codigo Alimentario Argen-tino modificatoria del Art 982 (Res 682007 y 1962007) Ley18 284 Buenos Aires Argentina 2007 httpwwwanmatgovarCODIGOACapitulo XII Agua 2007-05pdf
[26] J L Fernandez Turiel G GalindoM A Parada D GimenoMGarcıa-Valles and J Saavedra ldquoEstado actual del conocimientosobre el arsenico en el agua de Argentina y Chile origenmovilidad y transporterdquo inArsenico en Agua Origen movilidady tratamiento II Seminario Hispano-Latinoamericano sobreTemas Actuales de Hidrologıa Subterranea y IV Congreso Hidro-geologico Argentino pp 1ndash22 Rıo Cuarto Argentina 2005
[27] M L Gomez M T Blarasin and D E Martınez ldquoArsenic andfluoride in a loess aquifer in the central area of Argentinardquo Envi-ronmental Geology vol 57 no 1 pp 143ndash155 2009
[28] P L Smedley D G Kinniburgh D M J Macdonald et alldquoArsenic associations in sediments from the loess aquifer of LaPampa Argentinardquo Applied Geochemistry vol 20 no 5 pp989ndash1016 2005
[29] D L Ozsvath ldquoFluoride and environmental health a reviewrdquoReviews in Environmental Science and Biotechnology vol 8 no1 pp 59ndash79 2009
[30] E M Farfan Torres P M Naranjo A Boemo I Lomnicziand L Lorenzo ldquoDistribution of arsenic in groundwater in theChaco Salteno Argentinardquo in Workshop on as Distribution inIbero-America M I Litter Ed CyTED IBEROARSENAbstractBook pp 57ndash60 2006
[31] httpwwwjctoniccomincludemineralsboronhtm[32] M A Halim R K Majumder S A Nessa et al ldquoEvaluation
of processes controlling the geochemical constituents in deepgroundwater in Bangladesh spatial variability on arsenic andboron enrichmentrdquo Journal of HazardousMaterials vol 180 no1ndash3 pp 50ndash62 2010
[33] J BuschmannM Berg C Stengel andM L Sampson ldquoArsenicand manganese contamination of drinking water resources inCambodia coincidence of risk areaswith low relief topographyrdquoEnvironmental Science and Technology vol 41 no 7 pp 2146ndash2152 2007
[34] R A Beckman A S Mildvan and L A Loeb ldquoOn the fidelityof DNA replication manganese mutagenesis in vitrordquo Biochem-istry vol 24 no 21 pp 5810ndash5817 1985
[35] S-H Kim K Kim K-S Ko Y Kim and K-S Lee ldquoCo-con-tamination of arsenic andfluoride in the groundwater of uncon-solidated aquifers under reducing environmentsrdquoChemospherevol 87 no 8 pp 851ndash856 2012
NA not applicablelowastWHO World Health Organization have not established risk-based drink-ing water criteria for Al Ag Be Bi Co Fe Mn Mo Si Sr Ti V and ZnlowastlowastCAA Codigo Alimentario ArgentinolowastlowastlowastProvisional guideline value
and mobility of As and F in groundwater [1] Kim et al [35]suggested that the cocontamination of As and F observed inoxidizing aquifers in many countries is associated with thedesorption from the Fe-(hydr) oxides by the pH increasesThe correlations between As and F are generally very high inthose aquifers because the As released from Fe-(hydr) oxidesdoes not readily precipitate again in the oxidizing alkalinecondition This is consistent with our observations as manyof the samples show high pH values and moderate coefficientcorrelation value between As and F (1199032 = 050) Alsosolubility of Al minerals may be enhanced by the complex ofdissolved Al with F that is also released from volcanic glasses
Vanadium in groundwater ranged between lt100 (QL)and 2646 120583g Lminus1 The highest V concentration was found insample M31 (Table 2) Vanadium shows a moderated positivecorrelation with As (1199032 = 042) and is likely to be derivedfrom similar mineral sources (secondary Fe and Mn oxides)under the high pH conditions [1] Our results also indicatethat Mo in general appears in low concentrations (Table 3)Molybdenum is weakly correlated with As (1199032 = 020)
Gomez et al [27] suggest that V U B and Mo areenriched in volcanic materials and are mobilized as vanadatemolybdate borate and so forth under oxidizing conditionsAlternatively they are mobilized in alkaline solutions under
conditions of high pH and high HCO3
minus controlled bycarbonate reactions (eg the F may be forming anioniccomplexes with B Fe and Al)
Antimony (Sb) is ubiquity a GroupV of the periodic tableand is similar to As in aspects as chemical behavior andtoxicity to animals [5] The Sb concentrations in studiedsamples exceeded 20120583g Lminus1 WHO and CAA drinking waterguideline values in 45 (245) of the analyzed samples(Tables 3 and 4)
Cadmium reaches a maximum of 70120583g Lminus1 with mostsamples being less than 30 120583g Lminus1 As this element formscationic species in solution its mobilization is not favoredunder the alkaline conditions of the groundwater [1]
The presence of arsenic and heavy metals in the samplescollected from this region of Chaco in Argentina may be dueto local geochemical conditions that facilitate the transfer ofnaturally occurring arsenic from soil and sediment to thewaterThe people in the Comandante FernandezDepartmentmay be overexposed not only toAs but also to B CdMn andF Adverse health effects may appear in coming years Thisproblem is a serious concern for the local population
4 Conclusions
The results of the current study indicate that approximately91 of the groundwater samples used for consumptionby human and livestock from the Comandante FernandezDepartment (Chaco province Argentina) exceed the WHOprovisional guideline value of 10 120583g Lminus1 As recommended asa maximum allowable level in potable water
Evaporation potentiated in arid and semiarid zonefavors the increase of salinity and alkalinity the results is alow quality of the resource but is not conditioning the con-centration of As and F Hence factors other than evaporationsuch as desorption from metal oxides and possibly silicatereaction could be likely controlling As and F mobiliza-tion Furthermore arsenic associated trace elements may beabsorbed on the surface of iron and aluminum oxides andoxyhydroxides (hematite goethite Fe(OH)
3
and gibbsite)limiting the mobility of trace elements Groundwater withhigh pH values and high concentration of bicarbonate wouldfacilitate the dissolution of volcanic glass thus trace elementsmay enter groundwater cycles forming anionic complexes inalkaline solutions and acquiring great mobility
The hydrochemical trace in the region is characterizedby high salinity and high As and F concentrations whichis related to volcanism and hydrothermal activity from theAndes This association is often linked to presence of BCd Mo Mn and V indicating their common origin in thevolcanic glasses
Due to high As concentrations found in groundwaterserious health risk must be considered The population inthe area may be exposed to the chronic toxicological effectsof hydro arsenicism and fluorosis increasing the risks ofcontracting other diseases derived from them Since thegroundwater studied here constitutes the principal source ofdrinking water in the zone mitigation efforts should not belimited to As health risks from other toxic elements presentin drinking water must also be addressed in this region
ISRN Environmental Chemistry 11
Conflict of Interest
The authors declare that there is no conflict of interestsregarding the publication of this paper Its publication isapproved by all authors and tacitly or explicitly by the respon-sible authorities where the work was carried out and that ifaccepted it will not be published elsewhere in the same formin English or in any other language including electronicallywithout the written consent of the copyright-holder
Acknowledgments
This work was supported with funds from PI 3600005 Uni-versidad Nacional del Chaco Austral (UNCAus) Patricia SBlanes thanks the National Academy of Exact Physic andNatural Sciences for granting a PhD fellowship
References
[1] P L Smedley H B Nicolli DM JMacdonald A J Barros andJ O Tullio ldquoHydrogeochemistry of arsenic and other inorganicconstituents in groundwaters from La Pampa ArgentinardquoApplied Geochemistry vol 17 no 3 pp 259ndash284 2002
[2] S Muhammad M T Shah and S Khan ldquoHealth risk assess-ment of heavy metals and their source apportionment in drink-ingwater of Kohistan region northern PakistanrdquoMicrochemicalJournal vol 98 no 2 pp 334ndash343 2011
[3] S S Farıas V A Casa C Vazquez L Ferpozzi G N Pucci andI M Cohen ldquoNatural contamination with arsenic and othertrace elements in ground waters of Argentine Pampean PlainrdquoScience of the Total Environment vol 309 no 1ndash3 pp 187ndash1992003
[4] L Jarup ldquoHazards of heavy metal contaminationrdquo British Med-ical Bulletin vol 68 pp 167ndash182 2003
[5] World Health Organization (WHO) ldquoRecommendationsrdquo inGuidelines for Drinking Water Quality vol 1 Geneva Switzer-land 4th edition 2011
[6] C Hopenhayn ldquoArsenic in drinking water impact on humanhealthrdquo Elements vol 2 no 2 pp 103ndash107 2006
[7] S H Lamm and M B Kruse ldquoArsenic ingestion and bladdercancermortalitymdashwhat do the dose-response relationships sug-gest aboutmechanismrdquoHumanandEcological RiskAssessmentvol 11 no 2 pp 433ndash450 2005
[8] C-HWang C K Hsiao C-L Chen et al ldquoA review of the epi-demiologic literature on the role of environmental arsenicexposure and cardiovascular diseasesrdquo Toxicology and AppliedPharmacology vol 222 no 3 pp 315ndash326 2007
[9] J Bundschuh M I Litter F Parvez et al ldquoOne century ofarsenic exposure in Latin America a review of history andoccurrence from 14 countriesrdquo Science of the Total Environmentvol 429 pp 2ndash35 2012
[10] M T Alarcon-Herrera J Bundschuh B Nath et al ldquoCo-occurrence of arsenic and fluoride in groundwater of semi-aridregions in Latin America genesis mobility and remediationrdquoJournal of Hazardous Materials 2012
[11] E E Buchhamer P S Blanes RM Osicka andM C GimenezldquoEnvironmental risk assessment of arsenic and fluoride in thechaco province argentina research advancesrdquo Journal of Toxi-cology and Environmental Health A vol 75 no 22-23 pp 1437ndash1450 2012
[12] A Cabrera M Blarasin E Matteoda G Villalva and M LGomez ldquoComposicion quımica del agua subterranea en el surde Cordoba lınea de base hidroquımica o fondo natural enreferencia a arsenico y fluorrdquo in Aguas Superficiales y Sub-terraneas en el sur ae Cordoba Una Perspectiva GeoambientalM Blarasin S Degiovanni A Cabera and M Villegas Edspp 81ndash90 Universidad Nacional de Rıo Cuarto Rıo CuartoArgentina 2005
[13] P Bhattacharya M Claesson J Bundschuh et al ldquoDistributionand mobility of arsenic in the Rıo Dulce alluvial aquifers inSantiago del Estero Province Argentinardquo Science of the TotalEnvironment vol 358 no 1ndash3 pp 97ndash120 2006
[14] B Nicolli O C Tujchneider M C Paris M Blanco and A JBarros ldquoMovilidad del arsenico y oligoelementos asociados enaguas subterraneas del centro-norte de la provincia de Santa FeArgentinardquo in Proceedings of the Presencia de Fluor y Arsenicoen Aguas Subterraneas VI Congreso Hidrogeologico ArgentinoG Galindo J L Fernandez Turiel and A Storniolo Eds pp81ndash90 Santa Rosa La Pampa Argentina 2009
[15] H B Nicolli A Tineo J W Garcıa C M Falcon and PL Smedley ldquoMobilization of arsenic and other trace elementof health concern in groundwater from the Salı River BasinTucuman Province Argentinardquo Environmental Geochemistryand Health vol 34 no 2 pp 251ndash262 2012
[16] RMOsicka N Agullo C Herrera Ahuad andMC GimenezldquoEvaluacion de las concentraciones de fluoruro y arsenico enlas aguas subterraneas del Domo Central de la provincia delChacordquo Comunicaciones Cientıficas y Tecnologicas Univer-sidad Nacional del Nordeste 2002 httpwwwunneeduarunneviejaWebcytcyt200208-ExactasE-049pdf
[17] C E Fiorentino J D Paoloni M E Sequeira and P ArosteguyldquoThe presence of vanadium in groundwater of southeasternextreme the pampean region Argentina Relationship withother chemical elementsrdquo Journal of Contaminant Hydrologyvol 93 no 1ndash4 pp 122ndash129 2007
[18] P Sprechmann F G Acenaloza C Gaucher A C R Nogueiraand M J Perez ldquoTrasgresion Paranaense paleoestuario deltethys del miocenomedio yo superior en Sudamericardquo in Con-greso Latinoamericano de Geologıa Montevideo-UruguayAbstracts 1 CDRoom pp 10ndash15 Sociedad Latinoamericana deGeologıa 2001
[19] F Larroza and L S Farina ldquoCaracterizacion hidrogeologica delsistema acuıfero Yrenda (SAY) en Paraguay recurso compar-tido con y Boliviardquo in Proceedings of the IV Congreso Argentinode Hidrogeologıa TOMO II Argentinarıo Cuarto CordobaArgentina 2005
[20] E Popolizio P Y Serra and G O Hort ldquoLa clasificaciontaxonomica del Chacordquo Centro de Geociencia Aplicada vol 3no 1 pp 11ndash32 1980
[21] INTA ldquoInstituto Nacional de Tecnologıa AgropecuariardquoAgrometeorologıa httpwwwintagovarsaenzpemeteorolo-giameteorologiahtm
[22] M G Garcıa O Sracek D S Fernandez andM D V HidalgoldquoFactors affecting arsenic concentration in groundwaters fromNorthwestern Chaco-Pampean Plain Argentinardquo Environmen-tal Geology vol 52 no 7 pp 1261ndash1275 2007
[23] US Environmental Protection Agency ( EPA) ldquoArsenic Inor-ganic United States Environmental Protection Agency Inte-grated Risk Information System (IRIS) (CASRN 7440-38-2)rdquo1998 httpwwwepagovirissubst0278htm
12 ISRN Environmental Chemistry
[24] Comision Nacional de Alimentos (CONAL) Acta Nž 93Reunion Ordinaria 3011 y 0112-2011 (Prorroga Art 982 y 983del CAA)
[25] CAA (Codigo Alimentario Argentino) Cap XII Bebidashıdricas agua y agua gasificada In Codigo Alimentario Argen-tino modificatoria del Art 982 (Res 682007 y 1962007) Ley18 284 Buenos Aires Argentina 2007 httpwwwanmatgovarCODIGOACapitulo XII Agua 2007-05pdf
[26] J L Fernandez Turiel G GalindoM A Parada D GimenoMGarcıa-Valles and J Saavedra ldquoEstado actual del conocimientosobre el arsenico en el agua de Argentina y Chile origenmovilidad y transporterdquo inArsenico en Agua Origen movilidady tratamiento II Seminario Hispano-Latinoamericano sobreTemas Actuales de Hidrologıa Subterranea y IV Congreso Hidro-geologico Argentino pp 1ndash22 Rıo Cuarto Argentina 2005
[27] M L Gomez M T Blarasin and D E Martınez ldquoArsenic andfluoride in a loess aquifer in the central area of Argentinardquo Envi-ronmental Geology vol 57 no 1 pp 143ndash155 2009
[28] P L Smedley D G Kinniburgh D M J Macdonald et alldquoArsenic associations in sediments from the loess aquifer of LaPampa Argentinardquo Applied Geochemistry vol 20 no 5 pp989ndash1016 2005
[29] D L Ozsvath ldquoFluoride and environmental health a reviewrdquoReviews in Environmental Science and Biotechnology vol 8 no1 pp 59ndash79 2009
[30] E M Farfan Torres P M Naranjo A Boemo I Lomnicziand L Lorenzo ldquoDistribution of arsenic in groundwater in theChaco Salteno Argentinardquo in Workshop on as Distribution inIbero-America M I Litter Ed CyTED IBEROARSENAbstractBook pp 57ndash60 2006
[31] httpwwwjctoniccomincludemineralsboronhtm[32] M A Halim R K Majumder S A Nessa et al ldquoEvaluation
of processes controlling the geochemical constituents in deepgroundwater in Bangladesh spatial variability on arsenic andboron enrichmentrdquo Journal of HazardousMaterials vol 180 no1ndash3 pp 50ndash62 2010
[33] J BuschmannM Berg C Stengel andM L Sampson ldquoArsenicand manganese contamination of drinking water resources inCambodia coincidence of risk areaswith low relief topographyrdquoEnvironmental Science and Technology vol 41 no 7 pp 2146ndash2152 2007
[34] R A Beckman A S Mildvan and L A Loeb ldquoOn the fidelityof DNA replication manganese mutagenesis in vitrordquo Biochem-istry vol 24 no 21 pp 5810ndash5817 1985
[35] S-H Kim K Kim K-S Ko Y Kim and K-S Lee ldquoCo-con-tamination of arsenic andfluoride in the groundwater of uncon-solidated aquifers under reducing environmentsrdquoChemospherevol 87 no 8 pp 851ndash856 2012
The authors declare that there is no conflict of interestsregarding the publication of this paper Its publication isapproved by all authors and tacitly or explicitly by the respon-sible authorities where the work was carried out and that ifaccepted it will not be published elsewhere in the same formin English or in any other language including electronicallywithout the written consent of the copyright-holder
Acknowledgments
This work was supported with funds from PI 3600005 Uni-versidad Nacional del Chaco Austral (UNCAus) Patricia SBlanes thanks the National Academy of Exact Physic andNatural Sciences for granting a PhD fellowship
References
[1] P L Smedley H B Nicolli DM JMacdonald A J Barros andJ O Tullio ldquoHydrogeochemistry of arsenic and other inorganicconstituents in groundwaters from La Pampa ArgentinardquoApplied Geochemistry vol 17 no 3 pp 259ndash284 2002
[2] S Muhammad M T Shah and S Khan ldquoHealth risk assess-ment of heavy metals and their source apportionment in drink-ingwater of Kohistan region northern PakistanrdquoMicrochemicalJournal vol 98 no 2 pp 334ndash343 2011
[3] S S Farıas V A Casa C Vazquez L Ferpozzi G N Pucci andI M Cohen ldquoNatural contamination with arsenic and othertrace elements in ground waters of Argentine Pampean PlainrdquoScience of the Total Environment vol 309 no 1ndash3 pp 187ndash1992003
[4] L Jarup ldquoHazards of heavy metal contaminationrdquo British Med-ical Bulletin vol 68 pp 167ndash182 2003
[5] World Health Organization (WHO) ldquoRecommendationsrdquo inGuidelines for Drinking Water Quality vol 1 Geneva Switzer-land 4th edition 2011
[6] C Hopenhayn ldquoArsenic in drinking water impact on humanhealthrdquo Elements vol 2 no 2 pp 103ndash107 2006
[7] S H Lamm and M B Kruse ldquoArsenic ingestion and bladdercancermortalitymdashwhat do the dose-response relationships sug-gest aboutmechanismrdquoHumanandEcological RiskAssessmentvol 11 no 2 pp 433ndash450 2005
[8] C-HWang C K Hsiao C-L Chen et al ldquoA review of the epi-demiologic literature on the role of environmental arsenicexposure and cardiovascular diseasesrdquo Toxicology and AppliedPharmacology vol 222 no 3 pp 315ndash326 2007
[9] J Bundschuh M I Litter F Parvez et al ldquoOne century ofarsenic exposure in Latin America a review of history andoccurrence from 14 countriesrdquo Science of the Total Environmentvol 429 pp 2ndash35 2012
[10] M T Alarcon-Herrera J Bundschuh B Nath et al ldquoCo-occurrence of arsenic and fluoride in groundwater of semi-aridregions in Latin America genesis mobility and remediationrdquoJournal of Hazardous Materials 2012
[11] E E Buchhamer P S Blanes RM Osicka andM C GimenezldquoEnvironmental risk assessment of arsenic and fluoride in thechaco province argentina research advancesrdquo Journal of Toxi-cology and Environmental Health A vol 75 no 22-23 pp 1437ndash1450 2012
[12] A Cabrera M Blarasin E Matteoda G Villalva and M LGomez ldquoComposicion quımica del agua subterranea en el surde Cordoba lınea de base hidroquımica o fondo natural enreferencia a arsenico y fluorrdquo in Aguas Superficiales y Sub-terraneas en el sur ae Cordoba Una Perspectiva GeoambientalM Blarasin S Degiovanni A Cabera and M Villegas Edspp 81ndash90 Universidad Nacional de Rıo Cuarto Rıo CuartoArgentina 2005
[13] P Bhattacharya M Claesson J Bundschuh et al ldquoDistributionand mobility of arsenic in the Rıo Dulce alluvial aquifers inSantiago del Estero Province Argentinardquo Science of the TotalEnvironment vol 358 no 1ndash3 pp 97ndash120 2006
[14] B Nicolli O C Tujchneider M C Paris M Blanco and A JBarros ldquoMovilidad del arsenico y oligoelementos asociados enaguas subterraneas del centro-norte de la provincia de Santa FeArgentinardquo in Proceedings of the Presencia de Fluor y Arsenicoen Aguas Subterraneas VI Congreso Hidrogeologico ArgentinoG Galindo J L Fernandez Turiel and A Storniolo Eds pp81ndash90 Santa Rosa La Pampa Argentina 2009
[15] H B Nicolli A Tineo J W Garcıa C M Falcon and PL Smedley ldquoMobilization of arsenic and other trace elementof health concern in groundwater from the Salı River BasinTucuman Province Argentinardquo Environmental Geochemistryand Health vol 34 no 2 pp 251ndash262 2012
[16] RMOsicka N Agullo C Herrera Ahuad andMC GimenezldquoEvaluacion de las concentraciones de fluoruro y arsenico enlas aguas subterraneas del Domo Central de la provincia delChacordquo Comunicaciones Cientıficas y Tecnologicas Univer-sidad Nacional del Nordeste 2002 httpwwwunneeduarunneviejaWebcytcyt200208-ExactasE-049pdf
[17] C E Fiorentino J D Paoloni M E Sequeira and P ArosteguyldquoThe presence of vanadium in groundwater of southeasternextreme the pampean region Argentina Relationship withother chemical elementsrdquo Journal of Contaminant Hydrologyvol 93 no 1ndash4 pp 122ndash129 2007
[18] P Sprechmann F G Acenaloza C Gaucher A C R Nogueiraand M J Perez ldquoTrasgresion Paranaense paleoestuario deltethys del miocenomedio yo superior en Sudamericardquo in Con-greso Latinoamericano de Geologıa Montevideo-UruguayAbstracts 1 CDRoom pp 10ndash15 Sociedad Latinoamericana deGeologıa 2001
[19] F Larroza and L S Farina ldquoCaracterizacion hidrogeologica delsistema acuıfero Yrenda (SAY) en Paraguay recurso compar-tido con y Boliviardquo in Proceedings of the IV Congreso Argentinode Hidrogeologıa TOMO II Argentinarıo Cuarto CordobaArgentina 2005
[20] E Popolizio P Y Serra and G O Hort ldquoLa clasificaciontaxonomica del Chacordquo Centro de Geociencia Aplicada vol 3no 1 pp 11ndash32 1980
[21] INTA ldquoInstituto Nacional de Tecnologıa AgropecuariardquoAgrometeorologıa httpwwwintagovarsaenzpemeteorolo-giameteorologiahtm
[22] M G Garcıa O Sracek D S Fernandez andM D V HidalgoldquoFactors affecting arsenic concentration in groundwaters fromNorthwestern Chaco-Pampean Plain Argentinardquo Environmen-tal Geology vol 52 no 7 pp 1261ndash1275 2007
[23] US Environmental Protection Agency ( EPA) ldquoArsenic Inor-ganic United States Environmental Protection Agency Inte-grated Risk Information System (IRIS) (CASRN 7440-38-2)rdquo1998 httpwwwepagovirissubst0278htm
12 ISRN Environmental Chemistry
[24] Comision Nacional de Alimentos (CONAL) Acta Nž 93Reunion Ordinaria 3011 y 0112-2011 (Prorroga Art 982 y 983del CAA)
[25] CAA (Codigo Alimentario Argentino) Cap XII Bebidashıdricas agua y agua gasificada In Codigo Alimentario Argen-tino modificatoria del Art 982 (Res 682007 y 1962007) Ley18 284 Buenos Aires Argentina 2007 httpwwwanmatgovarCODIGOACapitulo XII Agua 2007-05pdf
[26] J L Fernandez Turiel G GalindoM A Parada D GimenoMGarcıa-Valles and J Saavedra ldquoEstado actual del conocimientosobre el arsenico en el agua de Argentina y Chile origenmovilidad y transporterdquo inArsenico en Agua Origen movilidady tratamiento II Seminario Hispano-Latinoamericano sobreTemas Actuales de Hidrologıa Subterranea y IV Congreso Hidro-geologico Argentino pp 1ndash22 Rıo Cuarto Argentina 2005
[27] M L Gomez M T Blarasin and D E Martınez ldquoArsenic andfluoride in a loess aquifer in the central area of Argentinardquo Envi-ronmental Geology vol 57 no 1 pp 143ndash155 2009
[28] P L Smedley D G Kinniburgh D M J Macdonald et alldquoArsenic associations in sediments from the loess aquifer of LaPampa Argentinardquo Applied Geochemistry vol 20 no 5 pp989ndash1016 2005
[29] D L Ozsvath ldquoFluoride and environmental health a reviewrdquoReviews in Environmental Science and Biotechnology vol 8 no1 pp 59ndash79 2009
[30] E M Farfan Torres P M Naranjo A Boemo I Lomnicziand L Lorenzo ldquoDistribution of arsenic in groundwater in theChaco Salteno Argentinardquo in Workshop on as Distribution inIbero-America M I Litter Ed CyTED IBEROARSENAbstractBook pp 57ndash60 2006
[31] httpwwwjctoniccomincludemineralsboronhtm[32] M A Halim R K Majumder S A Nessa et al ldquoEvaluation
of processes controlling the geochemical constituents in deepgroundwater in Bangladesh spatial variability on arsenic andboron enrichmentrdquo Journal of HazardousMaterials vol 180 no1ndash3 pp 50ndash62 2010
[33] J BuschmannM Berg C Stengel andM L Sampson ldquoArsenicand manganese contamination of drinking water resources inCambodia coincidence of risk areaswith low relief topographyrdquoEnvironmental Science and Technology vol 41 no 7 pp 2146ndash2152 2007
[34] R A Beckman A S Mildvan and L A Loeb ldquoOn the fidelityof DNA replication manganese mutagenesis in vitrordquo Biochem-istry vol 24 no 21 pp 5810ndash5817 1985
[35] S-H Kim K Kim K-S Ko Y Kim and K-S Lee ldquoCo-con-tamination of arsenic andfluoride in the groundwater of uncon-solidated aquifers under reducing environmentsrdquoChemospherevol 87 no 8 pp 851ndash856 2012
[24] Comision Nacional de Alimentos (CONAL) Acta Nž 93Reunion Ordinaria 3011 y 0112-2011 (Prorroga Art 982 y 983del CAA)
[25] CAA (Codigo Alimentario Argentino) Cap XII Bebidashıdricas agua y agua gasificada In Codigo Alimentario Argen-tino modificatoria del Art 982 (Res 682007 y 1962007) Ley18 284 Buenos Aires Argentina 2007 httpwwwanmatgovarCODIGOACapitulo XII Agua 2007-05pdf
[26] J L Fernandez Turiel G GalindoM A Parada D GimenoMGarcıa-Valles and J Saavedra ldquoEstado actual del conocimientosobre el arsenico en el agua de Argentina y Chile origenmovilidad y transporterdquo inArsenico en Agua Origen movilidady tratamiento II Seminario Hispano-Latinoamericano sobreTemas Actuales de Hidrologıa Subterranea y IV Congreso Hidro-geologico Argentino pp 1ndash22 Rıo Cuarto Argentina 2005
[27] M L Gomez M T Blarasin and D E Martınez ldquoArsenic andfluoride in a loess aquifer in the central area of Argentinardquo Envi-ronmental Geology vol 57 no 1 pp 143ndash155 2009
[28] P L Smedley D G Kinniburgh D M J Macdonald et alldquoArsenic associations in sediments from the loess aquifer of LaPampa Argentinardquo Applied Geochemistry vol 20 no 5 pp989ndash1016 2005
[29] D L Ozsvath ldquoFluoride and environmental health a reviewrdquoReviews in Environmental Science and Biotechnology vol 8 no1 pp 59ndash79 2009
[30] E M Farfan Torres P M Naranjo A Boemo I Lomnicziand L Lorenzo ldquoDistribution of arsenic in groundwater in theChaco Salteno Argentinardquo in Workshop on as Distribution inIbero-America M I Litter Ed CyTED IBEROARSENAbstractBook pp 57ndash60 2006
[31] httpwwwjctoniccomincludemineralsboronhtm[32] M A Halim R K Majumder S A Nessa et al ldquoEvaluation
of processes controlling the geochemical constituents in deepgroundwater in Bangladesh spatial variability on arsenic andboron enrichmentrdquo Journal of HazardousMaterials vol 180 no1ndash3 pp 50ndash62 2010
[33] J BuschmannM Berg C Stengel andM L Sampson ldquoArsenicand manganese contamination of drinking water resources inCambodia coincidence of risk areaswith low relief topographyrdquoEnvironmental Science and Technology vol 41 no 7 pp 2146ndash2152 2007
[34] R A Beckman A S Mildvan and L A Loeb ldquoOn the fidelityof DNA replication manganese mutagenesis in vitrordquo Biochem-istry vol 24 no 21 pp 5810ndash5817 1985
[35] S-H Kim K Kim K-S Ko Y Kim and K-S Lee ldquoCo-con-tamination of arsenic andfluoride in the groundwater of uncon-solidated aquifers under reducing environmentsrdquoChemospherevol 87 no 8 pp 851ndash856 2012
