Arsenic groundwater contamination in Bangladesh

Arsenic Arsenic groundwatergroundwatercontamination in Bangladeshcontamination in BangladeshPierre DoPierre Do pierre.do@ipb.fr pierre.do@ipb.fr

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