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Arsenic Arsenic groundwater groundwater contamination in Bangladesh contamination in Bangladesh Pierre Do Pierre Do [email protected] [email protected]
Arsenic Arsenic groundwatergroundwatercontamination in Bangladeshcontamination in BangladeshPierre DoPierre Do [email protected] [email protected]
Maximum Contaminant Level (MCL)Maximum Contaminant Level (MCL)
Maximum Contaminant Level (MCL)Maximum Contaminant Level (MCL)
10 ppb (µg/L)
50 ppb Bangladesh
Global arsenic occurrenceGlobal arsenic occurrence
Arsenic occurrence in AsiaArsenic occurrence in Asia
Bangladesh and West Bengal (India) : whereBangladesh and West Bengal (India) : wherethe most serious arsenic groundwater cases happen.the most serious arsenic groundwater cases happen.
10 ppb (µg.L-1)
1 ppb = 1/3000 getting cancer...
Maximum Contaminant Level (MCL)Maximum Contaminant Level (MCL)
10 ppb (µg.L-1)
50 ppb Bangladesh
Maximum Contaminant Level (MCL)Maximum Contaminant Level (MCL)
Survey conducted by DPHE/UNICEF in 1998-99 (with the British Geological Survey & Mott MacDonald Limited)
10 ppb 35-77 million50 ppb 22 million200 ppb 5,6 million
(MICS, 2009)
(< 150 m deep)
Sources of contaminationSources of contamination
Anthropogenic sourcesAnthropogenic sources
FertilizersFertilizers
Glass manufactureGlass manufacture Semiconductor chips Semiconductor chips
Coal fly ashCoal fly ash
PesticidesWood preservativesGlass manufacture
Coal fly ashSemiconductor chips
Other miscellaneous uses of arsenic
Anthropogenic sourcesAnthropogenic sources
Arsenic can occur naturally...Arsenic can occur naturally...
Green Lake, New ZealandGreen Lake, New Zealand
...and it causes elevated...and it causes elevatedarsenic concentrations.arsenic concentrations.
Weathered materials from the Weathered materials from the Himalayas form aquifer sediments.Himalayas form aquifer sediments.
Ganges-Padma-Meghna river brings Ganges-Padma-Meghna river brings sedimentary arsenic.sedimentary arsenic.
ArsenopyriteArsenopyrite
RealgarRealgar
Geochemical conditions :
Low pH, EhCompeting and complexing ions
Reaction kinetics
Redox reactionsRedox reactions
Microbiological activityMicrobiological activity
Organic matter(electron donor)
Anaerobic sediments (reductive environment)
Microbial reduction of Fe(III) and As(V)
Release of As(III) from sediments
Microbiological activityMicrobiological activity
Groundwater flow regime Groundwater flow regime controlscontrols......
… … the spatial variability of arsenic the spatial variability of arsenic concentrations in shallow aquifers.concentrations in shallow aquifers.
Main ways of human ingestion
Drinking contaminated waterDrinking contaminated water
Rice irrigated with arsenic-rich waterRice irrigated with arsenic-rich water
85 % of As can be absorbed.85 % of As can be absorbed.
Arum (kochu)Arum (kochu)
28 % of As can be absorbed.28 % of As can be absorbed.
Arsenic poisoning :Arsenic poisoning :ArsenicosisArsenicosis
Untreated people experienceUntreated people experienceseveral stages of the disease.several stages of the disease.
Melanosis and keratosisMelanosis and keratosis
Enlargement of liver, kidneys, spleenAbdominal pain, vomiting
Dryness/tightness in throatThirst, convulsions, cramps
Clammy sweats
SymptomsSymptoms
And later...
NephropathyHepatopathy
Limb lossLimb loss
Skin, lung, bladder, prostate cancer Immunological disorders
DiabetesReproductive & developmental problems
SymptomsSymptoms
“the worst mass poisoning in human history”
Smith et al., 2000;Smedley and Kinniburgh, 2002
One in five deaths in Bangladesh cause by arsenic (Habib et al. 2010).
International Community role ?
4 million citizens have access to 4 million citizens have access to arsenic-safe water...arsenic-safe water...
… … so only 2.9 % of the population of so only 2.9 % of the population of Bangladesh (S. Ahuja, 2008).Bangladesh (S. Ahuja, 2008).
It appears that financial backers are It appears that financial backers are not very enthusiastic about arsenic not very enthusiastic about arsenic
issues in Bangladesh...issues in Bangladesh...
Why do we have this BAD situation ?Why do we have this BAD situation ?
1970's: Surface water was used.1970's: Surface water was used.
In order to prevent from diseases, In order to prevent from diseases, various organizations decided to use various organizations decided to use groundwater, naturally contaminated.groundwater, naturally contaminated.
Focus on bacterial contamination,Focus on bacterial contamination,no elemental contaminationno elemental contamination
And today...And today...
Inadequate follow-through on the Inadequate follow-through on the strategy and guidelinesstrategy and guidelines
Inappropriate and inefficient Inappropriate and inefficient technology for arsenic mitigationtechnology for arsenic mitigation
Impractical approach : they do an Impractical approach : they do an implementation plan before installing implementation plan before installing
an appropriate technology.an appropriate technology.
...of deep tube wells restricts ...of deep tube wells restricts installation of other technologies.installation of other technologies.
Poor support fromPoor support fromdonor agencies...donor agencies...
Drink arsenic-free waterDrink arsenic-free water
Workable solutionsWorkable solutions
Implementation Plan for Arsenic Implementation Plan for Arsenic Mitigation of Bangladesh 2004Mitigation of Bangladesh 2004
(GOB)(GOB)
Improved dug wellsImproved dug wells
Pond sand filtersPond sand filters
Large-scale surface water treatmentLarge-scale surface water treatment
Rain water harvestingRain water harvesting
Reliable arsenic removal technologyReliable arsenic removal technology
Piped water supply systemsPiped water supply systems
Piped water supply systemsPiped water supply systems
BibliographyBibliography
Bibliography
● The problem of arsenic contamination of groundwater. Satinder Ahuja.
● Green Revolution Effects on Groundwater in West Bengal, India. Angela Cesere, Alex Aizenman, Mary Kate Heisler.
Bibliography
● web.worldbank.org● www.earth.columbia.edu● sitemaker.umich.edu● www.bpedia.org
““Be the change that you wish Be the change that you wish to see in the world.”to see in the world.”
Mahatma Gandhi Mahatma Gandhi
