Facts about Bangladesh Population:Area: Population density: Life expectancy: Infant mortality: Average annual income: Adult literacy: Bangladesh is overburdened with a large population, severe poverty, common illiteracy, and frequent natural disasters. (UNICEF, 2002) 137,000, ,000 square km 951 people/square km 59 years 82/1,000 live births (0 to 5 years) $380/person 52% of men, 29% of women

Solving the Largest Mass Poisoning in History: Arsenic-affected Drinking Water in Bangladesh Seth Frisbie, Ph.D.Bilqis Hoque, Ph.D.Donald Maynard, P.E. Erika Mitchell, Ph.D.Richard Ortega, Ph.D.Bibudhendra Sarkar, Ph.D. Raul SanchezMd. Siddiq, Ph.D.Ahmad Yusuf

The Problem Bangladesh’s surface water often contains life-threatening bacteria.Bangladesh’s surface water often contains life-threatening bacteria. Approximately 10,000,000 wells have been installed since 1971 to supply safe drinking water.Approximately 10,000,000 wells have been installed since 1971 to supply safe drinking water. Chronic arsenic poisoning was first diagnosed in 1993.Chronic arsenic poisoning was first diagnosed in Approximately 65,000,000 Bangladeshis are at risk of death from skin cancer caused by arsenic poisoning.Approximately 65,000,000 Bangladeshis are at risk of death from skin cancer caused by arsenic poisoning. Liver, colon, kidney, bladder, and lung cancers are also caused by drinking arsenic-contaminated water.Liver, colon, kidney, bladder, and lung cancers are also caused by drinking arsenic-contaminated water. (Photograph by Steven Brace, 1995)

Melanosis of the chest

Keratosis of the palms (Photograph by Dhaka Community Hospital and Richard Wilson, 2002)

Keratosis of the feet

BlackfootDisease

Melanosis Keratosis

Initial Project Goals Provide technical training.Provide technical training. Evaluate analytical chemistry capability.Evaluate analytical chemistry capability. Determine the extent of arsenic-affected drinking water in Bangladesh.Determine the extent of arsenic-affected drinking water in Bangladesh. Determine the source of this arsenic.Determine the source of this arsenic. Identify options for providing safe drinking water.Identify options for providing safe drinking water.

The performance of some laboratories in Bangladesh. The results from Laboratory 1 are high by approximately a factor of 4.The results from Laboratory 1 are high by approximately a factor of 4. Laboratories 2 and 3 only recovered approximately 50% of the arsenic from the independent standards.Laboratories 2 and 3 only recovered approximately 50% of the arsenic from the independent standards. Sample Description IndependentLaboratoryResult (µg/L) Standard solution = 1,000 µg As/L Sample A (250 µg As/L) Sample A plus 6,300 µg As/L Laboratory 1 ““4,8911,10124,126 Standard solution = 1,000 µg As/L Sample B (310 µg As/L) Sample B plus 3,300 µg As/L Laboratory 2 ““ Standard solution = 1,000 µg As/L Sample B (310 µg As/L) Sample B plus 7,100 µg As/L Laboratory 3 ““ < > 1,000

The performance of the ICDDR,B laboratory. The recoveries of all independently prepared standards were within the acceptable 100 ± 25% range.The recoveries of all independently prepared standards were within the acceptable 100 ± 25% range. The recoveries of all matrix spikes, except undiluted samples analyzed for ferrous iron, were acceptable.The recoveries of all matrix spikes, except undiluted samples analyzed for ferrous iron, were acceptable. AnalyteIndependent Standard Recovery Sample Matrix Spike Recovery Arsenic (As) 83% 89  11% Ferrous iron (Fe 2+ ) 93  10% 34  23% without dilution 96  13% with 1 to 10 dilution Total iron (Fe) 95% 120  12% with 1 to 10 dilution Sulfate (SO 4 2- ) 106% 106  20% Chloride (Cl - ) 114% 90  15% Phosphate (PO 4 3- ) 88% 84  2%

Locations of tubewells that contained interfering metals are labeled with the letter “E”.Locations of tubewells that contained interfering metals are labeled with the letter “E”. This was the first indication that non-arsenic toxins are widely distributed in Bangladesh’s drinking water.This was the first indication that non-arsenic toxins are widely distributed in Bangladesh’s drinking water. Map of average iron concentration (mg/L).

50% of Bangladesh’s area contains groundwater with manganese concentrations greater than the WHO drinking water guideline.50% of Bangladesh’s area contains groundwater with manganese concentrations greater than the WHO drinking water guideline. Manganese is a known mutagen.Manganese is a known mutagen. The accumulation of manganese may cause hepatic encephalopathy.The accumulation of manganese may cause hepatic encephalopathy. In addition, the chronic ingestion of manganese in drinking water is associated with neurological damage.In addition, the chronic ingestion of manganese in drinking water is associated with neurological damage. Map of manganese concentration (mg/L).

3% of Bangladesh’s area contains groundwater with lead concentrations greater than the WHO drinking water guideline.3% of Bangladesh’s area contains groundwater with lead concentrations greater than the WHO drinking water guideline. Lead is a “possible human carcinogen” due to inconclusive evidence of human and sufficient evidence of animal carcinogenicity.Lead is a “possible human carcinogen” due to inconclusive evidence of human and sufficient evidence of animal carcinogenicity. In addition, lead also causes many non-carcinogenic disorders in humans.In addition, lead also causes many non-carcinogenic disorders in humans. Map of lead concentration (mg/L).

< 1% of Bangladesh’s area contains groundwater with nickel concentrations greater than the WHO drinking water guideline.< 1% of Bangladesh’s area contains groundwater with nickel concentrations greater than the WHO drinking water guideline. Nickel is a “probable human carcinogen”.Nickel is a “probable human carcinogen”. Map of nickel concentration (mg/L).

< 1% of Bangladesh’s area contains groundwater with chromium concentrations greater than the WHO drinking water guideline.< 1% of Bangladesh’s area contains groundwater with chromium concentrations greater than the WHO drinking water guideline. The International Agency for Research on Cancer categorizes Cr(VI) as “carcinogenic to humans” and Cr(III) as “not classifiable”.The International Agency for Research on Cancer categorizes Cr(VI) as “carcinogenic to humans” and Cr(III) as “not classifiable”. However, the USEPA lists total chromium in drinking water as having “inadequate or no human and animal evidence of carcinogenicity”.However, the USEPA lists total chromium in drinking water as having “inadequate or no human and animal evidence of carcinogenicity”. Map of total chromium concentration (mg/L).

a Assuming Bangladesh has 137,000,000 people and 97% of its population drinks well water. Estimated number of Bangladeshis drinking water with metal concentrations above WHO guidelines. Metal Carcinogenic Potential WHO Guideline (µg/L) Percent of Bangladesh’s Area Exceeding WHO Guideline Number of Bangladeshis Drinking Unsafe Water a AsMnPbNiCr Known carcinogen Noncarcinogen Possible carcinogen Probable carcinogen Noncarcinogen < 1 65,000,00066,000,0004,000,000 < 1,300,000 Tens of millions of Bangladeshis are drinking water that exceeds WHO health-based guidelines for arsenic, manganese, lead, nickel, and chromium.Tens of millions of Bangladeshis are drinking water that exceeds WHO health-based guidelines for arsenic, manganese, lead, nickel, and chromium. Chronic arsenic poisoning is the most significant health risk.Chronic arsenic poisoning is the most significant health risk. Multimetal health effects are possible.Multimetal health effects are possible.

Multimetal Health Effects Antimony increases arsenic toxicity and was detected in 98% of wells.Antimony increases arsenic toxicity and was detected in 98% of wells. Conversely, zinc and selenium decrease arsenic toxicity and were often deficient in Bangladesh’s diet.Conversely, zinc and selenium decrease arsenic toxicity and were often deficient in Bangladesh’s diet. Estimated exposures to arsenic, zinc, and selenium from Bangladesh’s drinking water, rice, and soil. Metal Recommended Dietary Allowance (μg/day) Exposure from Water, Rice, and Soil (μg/day) AsZnSe Not determined 11, ,30046

Groundwater samples were collected from 120 villages.Groundwater samples were collected from 120 villages. 4 to 6 tubewells were sampled in each of these villages.4 to 6 tubewells were sampled in each of these villages. Map of sampling locations.

45% of Bangladesh’s area contains groundwater with arsenic concentrations greater than the 50- µ g/L national standard.45% of Bangladesh’s area contains groundwater with arsenic concentrations greater than the 50- µ g/L national standard. Approximately 65,000,000 Bangladeshis are at risk of disease and death from chronic arsenic poisoning.Approximately 65,000,000 Bangladeshis are at risk of disease and death from chronic arsenic poisoning. This wide-spread distribution suggests that the source of arsenic is geological.This wide-spread distribution suggests that the source of arsenic is geological. Map of average arsenic concentration (mg/L).

Potential Sources of Arsenic Hypothesis #1: The arsenic is being released by oxidizing an iron/sulfur mineral.Hypothesis #1: The arsenic is being released by oxidizing an iron/sulfur mineral. When the water table is lowered by groundwater pumping, the sulfur reacts with air, releasing arsenic.When the water table is lowered by groundwater pumping, the sulfur reacts with air, releasing arsenic. Therefore, the use of groundwater for irrigation should be stopped to minimize this release of arsenic.Therefore, the use of groundwater for irrigation should be stopped to minimize this release of arsenic. Hypothesis #2: The arsenic is being released by reducing an iron/non-sulfur mineral.Hypothesis #2: The arsenic is being released by reducing an iron/non-sulfur mineral. Arsenic might also be released as arsenate or arsenite by anion exchange with chloride, phosphate, or other anions.Arsenic might also be released as arsenate or arsenite by anion exchange with chloride, phosphate, or other anions. Therefore, the use of groundwater for irrigation should NOT be stopped.Therefore, the use of groundwater for irrigation should NOT be stopped.

Bangladesh had a famine in 1974 when its population was 71,000,000 and it could only produce 1 crop/year because of limited irrigation.Bangladesh had a famine in 1974 when its population was 71,000,000 and it could only produce 1 crop/year because of limited irrigation. Bangladesh currently feeds its 137,000,000 people because widespread irrigation produces 4 crops/year.Bangladesh currently feeds its 137,000,000 people because widespread irrigation produces 4 crops/year. Therefore, stopping irrigation could deny food to 66,000,000 Bangladeshis.Therefore, stopping irrigation could deny food to 66,000,000 Bangladeshis. The implications of stopping irrigation in Bangladesh. YearPopulation Agricultural Productivity ,000,000 1 Crop/Year ,000,000 4 Crops/Year

Map of average arsenic concentration (mg/L). Map of average sulfide concentration (mg/L). If Hypothesis #1 is correct and arsenic is being released from an iron/sulfur mineral, the concentrations of arsenic and inorganic sulfur should be correlated.If Hypothesis #1 is correct and arsenic is being released from an iron/sulfur mineral, the concentrations of arsenic and inorganic sulfur should be correlated. However, the concentrations of arsenic and sulfide are NOT correlated.However, the concentrations of arsenic and sulfide are NOT correlated.

Map of average arsenic concentration (mg/L). Map of average sulfate concentration (mg/L). Moreover, the concentrations of arsenic and sulfate are NOT correlated.Moreover, the concentrations of arsenic and sulfate are NOT correlated. Therefore, Hypothesis #1 is NOT generally correct and the use of groundwater for irrigation should NOT be stopped in this famine- prone country.Therefore, Hypothesis #1 is NOT generally correct and the use of groundwater for irrigation should NOT be stopped in this famine- prone country.

If Hypothesis #2 is correct and arsenic is being released by reducing an iron/non-sulfur mineral, the concentration of arsenic should increase as oxidation-reduction potential decreases.If Hypothesis #2 is correct and arsenic is being released by reducing an iron/non-sulfur mineral, the concentration of arsenic should increase as oxidation-reduction potential decreases. Graph of arsenic concentration (mg/L) versus oxidation-reduction (mV).

Map of average arsenic concentration (mg/L). Map of average chloride concentration (mg/L). In addition to dissolution in a reducing environment, arsenic might also be released as arsenate or arsenite by anion exchange with chloride.In addition to dissolution in a reducing environment, arsenic might also be released as arsenate or arsenite by anion exchange with chloride.

Map of average arsenic concentration (mg/L). Map of average phosphate concentration (mg/L). Moreover, arsenic might also be released as arsenate or arsenite by anion exchange with phosphate, or other anions.Moreover, arsenic might also be released as arsenate or arsenite by anion exchange with phosphate, or other anions. Therefore, Hypothesis # 2 may be correct and the use of groundwater for irrigation should NOT be stopped in this famine-prone country.Therefore, Hypothesis # 2 may be correct and the use of groundwater for irrigation should NOT be stopped in this famine-prone country.

Approximately 200 µg of arsenic per day are consumed from water, rice, and soil.Approximately 200 µg of arsenic per day are consumed from water, rice, and soil. Estimated Exposure to Arsenic in Bangladesh from Water, Rice, and Soil

REMEDY #1: Testing Can Provide Safe Water to Millions. Map of average arsenic concentration (mg/L). Map of minimum arsenic concentration (mg/L). 45% of Bangladesh’s neighborhoods contain groundwater with average arsenic concentrations greater than the 50-µg/L national standard.45% of Bangladesh’s neighborhoods contain groundwater with average arsenic concentrations greater than the 50-µg/L national standard. 15% of Bangladesh’s neighborhoods contain groundwater with minimum arsenic concentrations greater than this standard.15% of Bangladesh’s neighborhoods contain groundwater with minimum arsenic concentrations greater than this standard. Therefore, 85% of Bangladesh’s neighborhoods have at least 1 tubewell that does not require treatment for arsenic removal prior to drinking.Therefore, 85% of Bangladesh’s neighborhoods have at least 1 tubewell that does not require treatment for arsenic removal prior to drinking.

As a result of this discovery, groundwater testing has become a major component of an overall strategy for providing safe drinking water to the people of Bangladesh.As a result of this discovery, groundwater testing has become a major component of an overall strategy for providing safe drinking water to the people of Bangladesh. Tubewells are considered safe and marked with green paint if the arsenic concentration is less than or equal to the 50-µg/L national standard.Tubewells are considered safe and marked with green paint if the arsenic concentration is less than or equal to the 50-µg/L national standard. Conversely, tubewells are considered unsafe and marked with red paint if the arsenic concentration is greater than 50 µg/L.Conversely, tubewells are considered unsafe and marked with red paint if the arsenic concentration is greater than 50 µg/L. Testing Can Provide Safe Water to Millions (Photograph by The World Bank Group, 2005)

The vertical distribution of arsenic in groundwater (mg/L) based on adjacent pairs of “very deep” (67 to 335 m) and “shallow” (less than 28 m) tubewells. Drilling deeper tubewells can access water with markedly less arsenic.Drilling deeper tubewells can access water with markedly less arsenic. This approach should be used in the 15% of Bangladesh that cannot find drinking water with arsenic concentrations less than the national standard from existing tubewells within their village.This approach should be used in the 15% of Bangladesh that cannot find drinking water with arsenic concentrations less than the national standard from existing tubewells within their village. REMEDY #2: Drilling Deeper Tubewells May Access Safe Water.

The quality of water entering and leaving a storage tank which supplies drinking water to 300 people. The arsenic concentration is lowered from 160 to < 2 µg/L.The arsenic concentration is lowered from 160 to < 2 µg/L. The oxygen in air converts arsenic and iron to a solid which settles to the bottom of the tank.The oxygen in air converts arsenic and iron to a solid which settles to the bottom of the tank. REMEDY #3: Treatment Can Provide Safe Water. ParameterInfluentEffluent Arsenic (µg/L) Oxidation-reduction potential (millivolts) pH Conductivity (microsemans) Temperature ( o C) Total iron (µg/L) Sulfate (µg/L) Sulfide (µg/L) Chloride (µg/L) Phosphate (µg/L) NANANANANA < ,400 < 1,000 < 30 16,0001,300

Conclusions and Recommendations Arsenic is the most significant health risk in Bangladesh’s tubewell water.Arsenic is the most significant health risk in Bangladesh’s tubewell water. This arsenic is naturally occurring. Restricting irrigation will not solve the arsenic problem; however, it will cause a famine.This arsenic is naturally occurring. Restricting irrigation will not solve the arsenic problem; however, it will cause a famine. Bangladesh’s tubewell water also contains unsafe levels of manganese, lead, nickel, and chromium. Contour maps suggest these toxins extend beyond Bangladesh’s borders into India.Bangladesh’s tubewell water also contains unsafe levels of manganese, lead, nickel, and chromium. Contour maps suggest these toxins extend beyond Bangladesh’s borders into India. The severity of chronic arsenic poisoning in Bangladesh might be magnified by exposure to antimony, a lack of dietary zinc, and a lack of dietary selenium.The severity of chronic arsenic poisoning in Bangladesh might be magnified by exposure to antimony, a lack of dietary zinc, and a lack of dietary selenium. Food should also be tested for arsenic and other toxic metals.Food should also be tested for arsenic and other toxic metals.

Conclusions and Recommendations Periodically testing every tubewell so that people can make informed choices about their drinking water is the quickest and cheapest solution.Periodically testing every tubewell so that people can make informed choices about their drinking water is the quickest and cheapest solution. Other solutions include drilling deeper wells and using water treatment systems.Other solutions include drilling deeper wells and using water treatment systems. All proposed solutions need to be evaluated for effectiveness, affordability, and acceptability.All proposed solutions need to be evaluated for effectiveness, affordability, and acceptability.

SourcesPrimary: Frisbie, S.H., D.M. Maynard, and B.A. Hoque The nature and extent of arsenic-affected drinking water in Bangladesh. In Metals and Genetics. Ed. by B. Sarkar. Plenum Publishing Company. New York, NY. Pp Frisbie, S.H., D.M. Maynard, and B.A. Hoque The nature and extent of arsenic-affected drinking water in Bangladesh. In Metals and Genetics. Ed. by B. Sarkar. Plenum Publishing Company. New York, NY. Pp Frisbie, S.H., R. Ortega, D.M. Maynard, and B. Sarkar The concentrations of arsenic and other toxic elements in Bangladesh’s drinking water. Environmental Health Perspectives. 110(11): Frisbie, S.H., R. Ortega, D.M. Maynard, and B. Sarkar The concentrations of arsenic and other toxic elements in Bangladesh’s drinking water. Environmental Health Perspectives. 110(11): Frisbie, S.H., E.J. Mitchell, A.Z. Yusuf, M.Y. Siddiq, R.E. Sanchez, R. Ortega, D.M. Maynard, and B. Sarkar The development and use of an innovative laboratory method for measuring arsenic in drinking water from western Bangladesh. Environmental Health Perspectives. 113(9): Frisbie, S.H., E.J. Mitchell, A.Z. Yusuf, M.Y. Siddiq, R.E. Sanchez, R. Ortega, D.M. Maynard, and B. Sarkar The development and use of an innovative laboratory method for measuring arsenic in drinking water from western Bangladesh. Environmental Health Perspectives. 113(9):

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