Determination of some Endocrine Disruptors in Determination of some Endocrine Disruptors in a Sewage Treatment Oxidation Pond and a a Sewage Treatment Oxidation Pond and a

Receiving Stream by High Performance Liquid Receiving Stream by High Performance Liquid Chromatography and Inductively Coupled Chromatography and Inductively Coupled

Plasma-Mass SpectrometryPlasma-Mass SpectrometryN. TortoN. Torto

Department of Chemistry, Rhodes University, Department of Chemistry, Rhodes University, Grahamstown 6140, South AfricaGrahamstown 6140, South Africa

A.O. Ogunfowokan, E.K. Okoh, and A.A.AdenugaA.O. Ogunfowokan, E.K. Okoh, and A.A.Adenuga

Department of Chemistry, Obafemi Awolowo Department of Chemistry, Obafemi Awolowo University, Ile-Ife, 220005 NigeriaUniversity, Ile-Ife, 220005 Nigeria

What are Endocrine disruptors?What are Endocrine disruptors?Endocrine disruptorsEndocrine disruptors (sometimes referred to as (sometimes referred to as hormonally active agentshormonally active agents) are ) are exogenous substances that substances that act like act like hormones in the in the endocrine system and disrupt the and disrupt the physiologic function of physiologic function of endogenous hormones hormones Substances that stop the production or block the Substances that stop the production or block the transmission of hormones in the body and often interfere transmission of hormones in the body and often interfere with developmentwith developmentEndocrine disrupting compounds encompass a variety of Endocrine disrupting compounds encompass a variety of chemical classes, including pesticides, compounds used in chemical classes, including pesticides, compounds used in the plastics industry and in consumer products, and other the plastics industry and in consumer products, and other industrial by-products and pollutants industrial by-products and pollutants A large number of environmental pollutants including A large number of environmental pollutants including alkylphenolic compounds, polychlorinated biphenyls, and alkylphenolic compounds, polychlorinated biphenyls, and heavy metals including lead, mercury, cadmium and arsenic heavy metals including lead, mercury, cadmium and arsenic have been shown to disrupt endocrine functions in animals have been shown to disrupt endocrine functions in animals (Susan and John, 2001; Wu et al., 2003; Lee et al., 2003).(Susan and John, 2001; Wu et al., 2003; Lee et al., 2003).

Any Adverse Health Effects?Any Adverse Health Effects?

Endocrine disrupting chemicals have been proposed as a potential Endocrine disrupting chemicals have been proposed as a potential cause of a numerous human health problems such as:cause of a numerous human health problems such as:Birth defects; alterations in sexual and functional development Birth defects; alterations in sexual and functional development (Thomas and Colborn 1992); (Thomas and Colborn 1992); neurologic disorders, diabetes mellitus, immunologic disorder neurologic disorders, diabetes mellitus, immunologic disorder (Smoger et al,1993) (Smoger et al,1993) early puberty in young girls (Colon et al., 2000;Zacharids et al.., early puberty in young girls (Colon et al., 2000;Zacharids et al.., 1970), 1970), Breast cancer (Wolff et al., 1993, Steingraber et al.,1997, Breast cancer (Wolff et al., 1993, Steingraber et al.,1997, contribution to subfertility (Newbold, 1995), contribution to subfertility (Newbold, 1995), Reduced physical stamina (Guillette,et al., 1998)Reduced physical stamina (Guillette,et al., 1998)Reduced sperm counts and un-descended testes (Toppari et Reduced sperm counts and un-descended testes (Toppari et al.,1996) and al.,1996) and Enlargement/reduction of prostate (vom Saal et al., 1997).Enlargement/reduction of prostate (vom Saal et al., 1997).Inter-sex in fish e.g. fish from River Tames in LondonInter-sex in fish e.g. fish from River Tames in London

Occurrence of Endocrine Occurrence of Endocrine Disruptors (Phthalates)Disruptors (Phthalates)

Phthalates are components of many consumables, including:Phthalates are components of many consumables, including: Personal- carePersonal- carePaintsPaintsIndustrial plastics, and Industrial plastics, and Certain medical devices and pharmaceuticals (ATSDR, 1993, David Certain medical devices and pharmaceuticals (ATSDR, 1993, David et al., 1999). et al., 1999). Surface waters of south western Nigeria (Ogunfowokan and Fatoki Surface waters of south western Nigeria (Ogunfowokan and Fatoki 1993a&b; Ogunfowokan et al. 2006; Torto et al. 2007)1993a&b; Ogunfowokan et al. 2006; Torto et al. 2007)Phthalates are moderately persistent and, as a consequence of their Phthalates are moderately persistent and, as a consequence of their wide use, are the most abundant man-made chemicals in the wide use, are the most abundant man-made chemicals in the environment (Jobling et al., 1995).environment (Jobling et al., 1995). They are not chemically bound to the polymer matrices of the They are not chemically bound to the polymer matrices of the products but are present as a mobile component, significant products but are present as a mobile component, significant migration of them into the environment is inevitable. migration of them into the environment is inevitable.

Occurrence of Endocrine Occurrence of Endocrine Disruptors (Lead, Cadmium and Disruptors (Lead, Cadmium and

Arsenic)Arsenic)

Sources of Lead include: paint, Inks and dyes, Vehicular Sources of Lead include: paint, Inks and dyes, Vehicular emission, Plastics and chemicals, Dust in the roof void emission, Plastics and chemicals, Dust in the roof void etc (etc (http://www.lead.org.au/fs/fst2.html))Cadmium is released into the environment from mining Cadmium is released into the environment from mining and metal processing operations, burning fuels, making and metal processing operations, burning fuels, making and using phosphate fertilizers, and disposing of metal and using phosphate fertilizers, and disposing of metal products.products. Arsenic is found in the natural environment in some Arsenic is found in the natural environment in some abundance in the Earth’s crust and in small quantities in abundance in the Earth’s crust and in small quantities in rock, soil, water and air. It is present in many different rock, soil, water and air. It is present in many different minerals. Industrial processes such as mining, smelting minerals. Industrial processes such as mining, smelting and coal-fired power plants are other sources and coal-fired power plants are other sources

What are Phthalate Esters?What are Phthalate Esters?

Phthalates are dialkyl or alkyl Phthalates are dialkyl or alkyl aryl esters of phthalic acid with aryl esters of phthalic acid with the general structure shown the general structure shown below where R1 and R2 can below where R1 and R2 can be various combinations of be various combinations of straight and branched alkyl straight and branched alkyl chain or aryl group.chain or aryl group.

Are persistent organic Are persistent organic pollutants (POPs) and liable to pollutants (POPs) and liable to undergo significant undergo significant biomagnificationbiomagnification

Chemicals that have high Chemicals that have high environmental toxicity to environmental toxicity to humans and other organismshumans and other organisms

Health Effects of Pb, Cd and AsHealth Effects of Pb, Cd and AsLeadLead

For pregnant women, elevated Pb concentrations increase the risk of For pregnant women, elevated Pb concentrations increase the risk of hypertension and birth defects (Rabinowitz, 1988); reduction in the IQ of hypertension and birth defects (Rabinowitz, 1988); reduction in the IQ of Children (Ogunfowokan et al. 2000).Children (Ogunfowokan et al. 2000).

CadmiumCadmiumHealth effects of Cd are: Ittai-Ittai diseases, it also has mutagenic, Health effects of Cd are: Ittai-Ittai diseases, it also has mutagenic, carcinogenic and teratogenic effects (Fischer, 1987; Friberg, et al., 1986; carcinogenic and teratogenic effects (Fischer, 1987; Friberg, et al., 1986; Heinrich, 1988).Heinrich, 1988).

ArsenicArsenicHealth effects of Arsenic are: decreased production of red and white Health effects of Arsenic are: decreased production of red and white blood cells, skin changes and lung irritation, infertility and miscarriages blood cells, skin changes and lung irritation, infertility and miscarriages with women, and it can cause skin disturbances, heart disruptions and with women, and it can cause skin disturbances, heart disruptions and brain damage with both men and women, inorganic arsenic can damage brain damage with both men and women, inorganic arsenic can damage DNA (DNA (http://www.lenntech.com/periodic-chart-elements/as-en.htm#ixzz0QXN5ykWO))Humans may be exposed to Arsenic, Lead and Cadmium through food, Humans may be exposed to Arsenic, Lead and Cadmium through food, water and air.water and air.

Generally, endocrine disruptors have the Generally, endocrine disruptors have the potential to mimic, or in some cases potential to mimic, or in some cases block, the effects of the endogenous block, the effects of the endogenous hormone. They are therefore, described hormone. They are therefore, described as endocrine disrupting chemicals, as endocrine disrupting chemicals, hormone disruptors or estrogen hormone disruptors or estrogen mimickers (Roberts, 1999; Colon et al., mimickers (Roberts, 1999; Colon et al., 2000).2000).They are not under normal control and They are not under normal control and cause unregulated activities, hence in cause unregulated activities, hence in some cases there may be hyper-function some cases there may be hyper-function (excessive function) or hypo-function (excessive function) or hypo-function (under function) The main target of the (under function) The main target of the endocrine disruptors is the endocrine endocrine disruptors is the endocrine system system

ENDOCRINE SYSTEM

Endocrine system Endocrine system

Major endocrine glands: 1. Pineal gland 2. Pituitary gland 3. Thyroid gland 4. Thymus 5. Adrenal gland 6. Pancreas 7. Ovary 8. Testes. Source: http://en.wikipedia.org/wiki/Endocrine_system

The endocrine system is instrumental in regulating metabolism, growth, development, puberty, tissue function and also plays a part in determining mood

Our Early efforts on Endocrine disruptorsOur Early efforts on Endocrine disruptorsDevelopment of methods for the quantitative determination of Development of methods for the quantitative determination of Phthalate Esters in Surface waters, sewage treatment oxidation Phthalate Esters in Surface waters, sewage treatment oxidation pond and Tap Water (Fatoki and Ogunfowokan 1993a &b, pond and Tap Water (Fatoki and Ogunfowokan 1993a &b, Ogunfowokan et al., 2006)Ogunfowokan et al., 2006)

Other work from the study area includes the determination of some Other work from the study area includes the determination of some physicochemical parameters in the sewage treatment oxidation physicochemical parameters in the sewage treatment oxidation pond (Ogunfowokan et al. 2005 & 2008)pond (Ogunfowokan et al. 2005 & 2008)

Fatoki, O.S. and Fatoki, O.S. and Ogunfowokan, A.O.Ogunfowokan, A.O. (1993b): Environment International 19, 619-623 (1993b): Environment International 19, 619-623

Fatoki, O.S. and Fatoki, O.S. and Ogunfowokan, A.O.Ogunfowokan, A.O. (1993a): International Journal of Environmental (1993a): International Journal of Environmental Studies: 44, 237-243.Studies: 44, 237-243.

A.O. Ogunfowokan,A.O. Ogunfowokan, , N.Torto , A.A.Adenuga and E.K.Okoh (2006):, N.Torto , A.A.Adenuga and E.K.Okoh (2006): Environmental Monitoring and Assessment 118 , 457-480 The Netherland)Environmental Monitoring and Assessment 118 , 457-480 The Netherland)

N. Torto, Lesego C. Mmualefe, J.F. Mwatseteza, B. Nkoane, L. Chimuka, M.M. Nindi and N. Torto, Lesego C. Mmualefe, J.F. Mwatseteza, B. Nkoane, L. Chimuka, M.M. Nindi and A.O. A.O. OgunfowokanOgunfowokan (2007): Journal of Chromatography A, 1153: 1–13 (2007): Journal of Chromatography A, 1153: 1–13

Ogunfowokan A.O.Ogunfowokan A.O.,, Adenuga A.A., Torto N., E.K.Okoh (2008) Adenuga A.A., Torto N., E.K.Okoh (2008) Environmental Monitoring Environmental Monitoring and Assessment. The Netherland 143: 25-41and Assessment. The Netherland 143: 25-41

Ogunfowokan A.O.,Ogunfowokan A.O., E.K. Okoh, A.A. Adenuga and O.I. Asubiojo (2005):Journal of E.K. Okoh, A.A. Adenuga and O.I. Asubiojo (2005):Journal of Applied Sciences 5 (1): 36-43.Applied Sciences 5 (1): 36-43.

Why this study?Why this study?Endocrine disruptors are of concern because of their Endocrine disruptors are of concern because of their subtle toxicity effects since they affect the normal subtle toxicity effects since they affect the normal function of the endocrine systemfunction of the endocrine system

Small but critical changes in the chemical makeup of an Small but critical changes in the chemical makeup of an environment are enough to trigger outcomes that could environment are enough to trigger outcomes that could lead to population decline and loss of bio-diversitylead to population decline and loss of bio-diversity

This study therefore, focused on the identification and This study therefore, focused on the identification and quantification of some phthalate esters and some heavy quantification of some phthalate esters and some heavy metals that have been implicated as endocrine metals that have been implicated as endocrine disruptors in a sewage treatment oxidation pond; as a disruptors in a sewage treatment oxidation pond; as a source and the impact on a receiving stream. source and the impact on a receiving stream.

Study area and sampling points

Figure 1 is the map of the study area showing the sampling sites. Measurement points from the sampling sites have been designated S1 to S8. Sample SR represents the reference point upstream before discharge of the effluent into the stream and serves as control.

The Obafemi Awolowo University campus has two Oxidation ponds A and B lying side by side. (Figure1). Each pond measures 150m by 32m, and is about 1.2m deep. A 5m wide dyke separates the ponds. The wastes are conveyed to the ponds through a network of concrete pipes of different diameters. Only one pond receives influents and waste water at a time. The sewage is retained in the pond for about 2 weeks during which algae, bacteria and other microorganisms act on them.

Each pond has a discharge channel through which effluents are discharged into the receiving stream. Site S1was located 30m away from the inlet to the pond, before the influent enters the pond. S2 was located at the inlet to the pond and S3 was located right on the pond about 50m away while site S4 represents the point of exit of effluents from the oxidation pond. S5 was a point located at the place where the pond's effluent enters the receiving river while sites S6 and S7 were located down stream, at approximately 15m and 100m respectively away from S5. S8 was located about 350m away from the confluence of Opa River and the receiving stream, which is about 800m away from S5. Site SR was the reference point and was located about 20m up stream from the point of discharge of the effluents into the receiving stream (S5).

S1

S6

S5

S7

S8 Abattoir

S2

S4

S3 B

ExperimentalExperimental

Chemicals and ReagentsChemicals and ReagentsAll reagents used in this study were of analytical All reagents used in this study were of analytical

grade and were further purified before use.grade and were further purified before use.

Ultra pure water was from a Milli-Q system supplied Ultra pure water was from a Milli-Q system supplied by Millipore (Bedford, MA, USA). N-hexane and by Millipore (Bedford, MA, USA). N-hexane and ethyl acetate were from Ultrafine Limited, ethyl acetate were from Ultrafine Limited, (Finchely,London). Acetonitrile was from Riedel-(Finchely,London). Acetonitrile was from Riedel-de Haën (Sigma-Aldrich, Laborchemikalien de Haën (Sigma-Aldrich, Laborchemikalien GmbH, Germany). Other reagents used were: GmbH, Germany). Other reagents used were: sodium chloride from Associated Chemical sodium chloride from Associated Chemical Enterprises, (Glenvista, RSA), sodium Enterprises, (Glenvista, RSA), sodium carbonate from SAARCHEM, (Muldersdrift, carbonate from SAARCHEM, (Muldersdrift, RSA), anhydrous sodium sulphate and RSA), anhydrous sodium sulphate and dichloromethane were obtained from Rochelle dichloromethane were obtained from Rochelle chemicals (Johannesburg, RSA) while chemicals (Johannesburg, RSA) while aluminum oxide was from Fluka Chemica aluminum oxide was from Fluka Chemica (Switzerland). HNO3 and HClO4 were obtained (Switzerland). HNO3 and HClO4 were obtained from BDH Chemicals (Poole, England).from BDH Chemicals (Poole, England).

Sample HandlingSample HandlingSamples for phthalate esters analysisSamples for phthalate esters analysis : were : were

collected in 2.5liter amber Winchester glass collected in 2.5liter amber Winchester glass bottles, which had been thoroughly washed and bottles, which had been thoroughly washed and rinsed with triply distilled water, oven dried and rinsed with triply distilled water, oven dried and finally rinsed with triply distilled finally rinsed with triply distilled dichloromethane. The bottles were rinsed dichloromethane. The bottles were rinsed thoroughly with the samples before they were thoroughly with the samples before they were finally filled. The mouths of bottles were finally filled. The mouths of bottles were covered with glass stopper after filling them covered with glass stopper after filling them with samples to avoid contamination from with samples to avoid contamination from plastic covers. Alteration of the organics due to plastic covers. Alteration of the organics due to microbial activities was prevented by microbial activities was prevented by acidification of the samples to pH 2 with acidification of the samples to pH 2 with concentrated hydrochloric acid immediately concentrated hydrochloric acid immediately after collection and samples were stored in after collection and samples were stored in refrigerator at about 40C prior to analysis.refrigerator at about 40C prior to analysis.

Samples for metals analysisSamples for metals analysis : were collected using : were collected using plastic bottles that have been previously plastic bottles that have been previously cleaned by washing in detergent, rinsed with cleaned by washing in detergent, rinsed with tap water, and later soaked in 10% HNO3 for 72 tap water, and later soaked in 10% HNO3 for 72 hours and finally rinsed with deionised water hours and finally rinsed with deionised water prior to usage. During sampling, sample bottles prior to usage. During sampling, sample bottles were rinsed with sampled water several times were rinsed with sampled water several times and then filled to the brim. The samples were and then filled to the brim. The samples were transported to the laboratory immediately and transported to the laboratory immediately and stored in the refrigerator at about 4ºC prior to stored in the refrigerator at about 4ºC prior to analysis.analysis.

Trace Organics analysis (Phthalates)Trace Organics analysis (Phthalates)

ExtractionsExtractionsUltra pure water was used as the blank Ultra pure water was used as the blank

sample. 1000mL aliquot of ultra sample. 1000mL aliquot of ultra pure water was measured into a 2 L pure water was measured into a 2 L beaker and acidified with beaker and acidified with concentrated HCl to pH 2, then concentrated HCl to pH 2, then saturated with about 20g of NaCl. saturated with about 20g of NaCl. This was extracted three times with This was extracted three times with 15ml of CH15ml of CH22ClCl22 each time. The each time. The CHCH22ClCl22 extracts were combined and extracts were combined and they contained phthalate esters and they contained phthalate esters and other organic contaminants. The other organic contaminants. The free fatty acids (FFA) interferences free fatty acids (FFA) interferences were removed by further extraction were removed by further extraction with 3 x 10mL 0.1M Nawith 3 x 10mL 0.1M Na22COCO33. The . The organic extracts after alkali organic extracts after alkali washing, were then dried over washing, were then dried over anhydrous Naanhydrous Na22SOSO44. The . The dichloromethane was subsequently dichloromethane was subsequently evaporated by purging with nitrogen evaporated by purging with nitrogen gas. The same procedure was gas. The same procedure was employed for real samples.employed for real samples.

Sample clean-upSample clean-up A 10 mL column was packed with A 10 mL column was packed with

about 12.5g of activated alumina about 12.5g of activated alumina prepared in a slurry form in n-prepared in a slurry form in n-hexane. The residue extracts were hexane. The residue extracts were redissolved in 2ml CHredissolved in 2ml CH22ClCl22 and and chromatographed through the chromatographed through the packed column.packed column.

Hydrocarbons and phthalate esters Hydrocarbons and phthalate esters were eluted successively from the were eluted successively from the column with 20mL of n-hexane and column with 20mL of n-hexane and 30mL ethyl acetate. The ethyl 30mL ethyl acetate. The ethyl acetate eluate was concentrated to acetate eluate was concentrated to 1ml by purging with nitrogen gas. 1ml by purging with nitrogen gas. This was diluted with 1mL This was diluted with 1mL acetonitrile for LC/MS analysis.acetonitrile for LC/MS analysis.

Quality assurance studyQuality assurance study

Quality assurance was carried out by recovery Quality assurance was carried out by recovery experiments in order to ascertain the precision and experiments in order to ascertain the precision and efficiency of the analytical procedure. This was efficiency of the analytical procedure. This was done by extracting a sample spiked with 10 mL of a done by extracting a sample spiked with 10 mL of a mixture of five authentic phthalate esters at a mixture of five authentic phthalate esters at a concentration of 1 mg/mL. Using a spiked sample concentration of 1 mg/mL. Using a spiked sample has the limitation that some analytes strongly has the limitation that some analytes strongly retained on the particles may not be extracted. retained on the particles may not be extracted. However, since no certified reference material was However, since no certified reference material was available to us when this study was conducted, this available to us when this study was conducted, this method was used for method validate.method was used for method validate.

Analyses of MetalsDigestion of water samples

The samples were digested using mixture of acids. The method adopted was described by Carrondo et al. (1979). 10mL of water sample was put in a pretreated Teflon beaker and 30ml of concentrated HN03 was added and the mixture was evaporated to dryness on a hot plate in a fume cupboard. This was allowed to cool and 5mL HNO3, 2mL 60% HClO4 and 6mL 40% HF acids were added. The resulting mixture was evaporated to dryness, and then 2mLHNO3 and HClO4 acids were added and evaporated to dryness to ensure that silicon and fluoride were removed. The final residue was re-dissolved in 2.5mL of 2M HNO3 and brought up to the mark of 25mL standard flask with distilled water.

A blank digestion was as well carried out for background correction. The worked-up samples above were analyzed using ICP-MS.

InstrumentalInstrumental

Phthalate EsterPhthalate Ester

Determination of phthalate esters was Determination of phthalate esters was achieved after separation using a achieved after separation using a HP1100 series HPLC system, Agilent HP1100 series HPLC system, Agilent Technologies (Waldbronn, Germany), Technologies (Waldbronn, Germany), equipped with a diode array detector and equipped with a diode array detector and thermostated column compartment. thermostated column compartment. Chromatographic separation was carried Chromatographic separation was carried out using a 250mm x 4.6mm i.d. out using a 250mm x 4.6mm i.d. Kromasil 100 C18 column with particle Kromasil 100 C18 column with particle size of 10μm, from SUPELCO (Bellefonte, size of 10μm, from SUPELCO (Bellefonte, USA). Separation was performed under USA). Separation was performed under gradient elution conditions using gradient elution conditions using acetonitrile and water as mobile phase, acetonitrile and water as mobile phase, with an injection volume of 25 µl and with an injection volume of 25 µl and flow rate of 1 ml/min, with the column flow rate of 1 ml/min, with the column temperature was set at 40 temperature was set at 40 C. The elution C. The elution gradient started with 50% acetonitrile, gradient started with 50% acetonitrile, which was increased linearly to 75% which was increased linearly to 75% over four minutes. Then over four over four minutes. Then over four minutes, it was changed to 100%, and minutes, it was changed to 100%, and the condition was maintained for twelve the condition was maintained for twelve minutes before returning to initial minutes before returning to initial percentage in four minutes percentage in four minutes

MetalsMetals

The metals As, Cd, and Pb were analyzed The metals As, Cd, and Pb were analyzed after acid digestion using a Finnigan after acid digestion using a Finnigan MAT Element 2 High Resolution MAT Element 2 High Resolution Inductively Coupled Plasma - Mass Inductively Coupled Plasma - Mass Spectrophotometer Finnigan (Bremen, Spectrophotometer Finnigan (Bremen, Germany). For ICP-MS analysis, the Germany). For ICP-MS analysis, the isotopes of the elements determined isotopes of the elements determined were; were; 111111Cd, Cd, 7575As and As and 208208Pb. Pb.

The RF power was 1.158kW, nebulizer gas The RF power was 1.158kW, nebulizer gas flow rate was 1.0L/min, cooling gas flow flow rate was 1.0L/min, cooling gas flow rate was 14.89L/min, with a detector rate was 14.89L/min, with a detector voltage 2398V.voltage 2398V.

RESULTS AND DISCUSSION

% Recovery of Phthalate Esters from Spiked Water Samples

Phthalate esters Percentage recovery %Standarddeviation

Coefficient of variation(Cv)%

Dimethyl phthalate (DMP) 68.43 2.56 3.74

Diethyl phthalate (DEP) 72.35 2.40 3.32

Diphenyl phthalate (DPhP) 46.36 1.81 3.91

Dibutyl phthalate (DBP), 85.60 2.06 2.42

Bis(2-ethylhexyl) phthalate (DEHP) 106.34 4.11 3.87

min0 5 10 15 20

mAU

0

250

500

750

1000

1250

1500

1750

2000

2250

*DAD1 A, Sig=254,16 Ref=850,40 (190504\STD-L4OC.D) - FLD1 A, Ex=235, Em=307 (190504\STD-L4OC.D)

5.17

7 D

MP

6.88

9 D

EP

9.14

5 D

PhP

9.54

1 B

UTY

L BE

NZO

ATE

10.3

26 D

BP

I5.8

63 D

EHP

16.7

55 D

OP

18.1

67 D

INP

Figure 2: Representative Chromatogram of mixture of Phthalate Esters obtained on HPLC

Levels of phthalate Esters in the Oxidation pond and the receiving Stream

0

20

40

60

80

100

120

con

cen

trat

ion

(m

g/L

)

S1 S2 S3 S4 SR S5 S6 S7 S8

sampling site

DMP

DEP

DPhP

DBP

DEHP

DOP

DINP

USEPA criteria of 3μg/L phthalates recommended for the protection of fish and other aquatic life in water and the SNAEL of 7.5–38.5μg/L for drinking water. This should give cause for great environmental concern. Peoples’ health downstream is at stake and so is the ‘health’ of the ecosystem.

Wave number cm-1 Assigned functional group

2,907 – 2,880 (s) C-H stretching vibration of CH3, CH3, and CH.

1720 (m) C =O stretching vibration of ester

1600-1400 (m) C=C aromatic ring

1140 – 1110 (m) C-O stretching vibration of ester

1250 1280 (m) C-O stretching vibration of benzoates

690 – 720 (w) di-substituted aromatic compound

S – strong absorption, m – medium absorption, w – weak absorption

Interpretation of infrared spectrum of phthalate esters in samples from Sewage treatment oxidation pond

AbeyDBP1 #16-137 RT: 0.11-0.98 AV: 122 NL: 4.15E8T: + c ms [ 125.00-325.00]

140 160 180 200 220 240 260 280 300 320

m/z

0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

85

90

95

100

Re

lative

Ab

un

da

nce

278.8

279.8

204.7

149.1 317.8280.8205.8 295.4150.1 278.1189.6 221.8 259.9148.3 236.7163.0 252.9182.8135.9

Mass Chromatogram of Dibutyl Phthalate Ester

Mean values for metals in the sewage treatment oxidation pond

Month Metals

Cd µg/L As µg/ L Pb µg/ L

July 17.59±

3.02

46.67±

12.25

21.69±

10.88

August 15.61±

4.13

62.03±

11.00

42.18±

9.13

September 4.70±

0.52

92.30±

20.13

51.56±

10.25

October 19.05±

2.71

94.22±

23.69

43.84±

4.99

November 11.13±

1.43

104.67±

1.76

64.57±

7.00

December 11.17±

1.51

96.27±

2.92

65.55±

13.85

Overallmean

13.26±

5.27

82.69± 22.88

48.24±

16.36

Average values for metals in the receiving stream

MonthMetal

Cd µg/L As µg/L Pb µg/L

July 16.03±

10.62

21.50±

9.81

8.29±

3.98

August 5.52±

2.40

45.45±

14.46

31.28±

4.85

September 5.98±

3.07

98.88±

12.49

24.18±

6.27

October 19.57±

2.55

74.74±

22.50

42.78±

4.97

November 5.05±

3.18

74.88±

11.07

39.93±

6.80

December 10.98± 2.78

40.06±

14.95

51.75±

8.94

Overallmean

10.53±

6.12

59.42± 28.53

33.12±

15.23

Average values for metals in the reference samples

MonthMetal

Cd µg/L As µg/L Pb µg/L

July 5.78±

1.16

<0.5 <0.50

August 3.54±

0.16

3.02±

1.01

3.35±

0.02

September 1.75±

0.08

4.88±

0.85

2.83±

0.06

October 4.14±

0.72

5.30±

2.01

5.34±

0.18

November 2.32±

0.07

1.10±

0.76

6.81±

0.78

December 2.27±

0.03

5.62±

2.26

7.20±

1.20

Overallmean

3.30±

1.51

3.98± 1.90

5.11±

1.98

Overallmean

13.26±

5.27

82.69± 22.88

48.24±

16.36

oxidation pond

Overallmean

10.53±

6.12

59.42± 28.53

33.12±

15.23

receiving stream

Overallmean

3.30±

1.51

3.98± 1.90

5.11±

1.98reference samples

Maximum allowable threshold of metals in water intended for human consumption and that will not constitute a threat to health: As = 10 μg/L (DWAF 1996); Pb = 100 μg/L (FEPA); Cd = 3 μg/L (WHO 1993)

Cd µg/L As µg/ L Pb µg/ L

Conclusion• The levels of phthalate ester plasticizers and metals were studied in a

sewage lagoon effluents and its receiving stream in this study. Liquid–liquid extraction and high performance liquid chromatography and Inductively Coupled Mass Spectrometry have been used for quantitative analysis of phthalate esters and metals.

• The results obtained showed high levels of phthalate esters, As, Cd and Pb in the sewage lagoon and the receiving stream with the former being higher in phthalates and metals than the latter.

• The discharge of the effluent from the sewage lagoon into the receiving stream led to increase in the concentrations of the analytes downstream and has therefore impacted the receiving stream.

Conclusion/RecommendationThis is unfortunate because lives of fish and aquatic biota in the

receiving stream are at risk and the rural dwellers that depend on the water from the receiving stream for various domestic purposes downstream untreated are at great risk of serious health effects due to phthalate esters and metals pollution.

The sewage lagoon serves as point source pollution into the receiving stream. There is therefore a need for urgent action by the authority in charge of the sewage lagoon to upgrade it to improve its treatment performance.

Thorough analysis and study of water from the stream before being used for domestic applications is therefore recommended to minimize the health risk. Future work should be carried out on fish and sediments of the receiving stream to ascertain biomagnifications of these analytes in these matrices.

Food for thought !!!!

Therefore, my beloved brethren, be ye steadfast, unmoveable, always abounding in the work of the LORD, for as much as ye know that your labour is not in vain in the Lord (I Corinthians 15 verse 58) KJV

Acknowledgement

I would like to appreciate the Local organizing committee of the Humboldt International conference and Stiftung /Foundation for the full sponsorship granted to me

Thank You all for your attention !!!!!!!!