A H Smith, Elena O. Lingas, Mizanur Rahman
The contamination of groundwater by arsenic in Bangladesh is the largest poisoning of a population in history, with millions of people exposed. This paper describes the history of the discovery of arsenic in drinking-water in Bangladesh and recommends intervention strategies. Tube-wells were installed to provide "pure water" to prevent morbidity and mortality from gastrointestinal disease. The water from the millions of tube-wells that were installed was not tested for arsenic contamination. Studies in other countries where the population has had long-term exposure to arsenic in groundwater indicate that 1 in 10 people who drink water containing 500 micrograms of arsenic per litre may ultimately die from cancers caused by arsenic, including lung, bladder and skin cancers. The rapid allocation of funding and prompt expansion of current interventions to address this contamination should be facilitated. The fundamental intervention is the identification and provision of arsenic-free drinking water. Arsenic is rapidly excreted in urine, and for early or mild cases, no specific treatment is required. Community education and participation are essential to ensure that interventions are successful; these should be coupled with follow-up monitoring to confirm that exposure has ended. Taken together with the discovery of arsenic in groundwater in other countries, the experience in Bangladesh shows that groundwater sources throughout the world that are used for drinking-water should be tested for arsenic.
Ross T. Nickson, J.M. McArthur, William Burgess, Kazi Matin Ahmed et al.
Ross T. Nickson, J.M. McArthur, Peter Ravenscroft, W. G. Burgess et al.
Marisa F. Naujokas, Beth Anderson, Habibul Ahsan, H. Vasken Aposhian et al.
BACKGROUND: Concerns for arsenic exposure are not limited to toxic waste sites and massive poisoning events. Chronic exposure continues to be a major public health problem worldwide, affecting hundreds of millions of persons. OBJECTIVES: We reviewed recent information on worldwide concerns for arsenic exposures and public health to heighten awareness of the current scope of arsenic exposure and health outcomes and the importance of reducing exposure, particularly during pregnancy and early life. METHODS: We synthesized the large body of current research pertaining to arsenic exposure and health outcomes with an emphasis on recent publications. DISCUSSION: Locations of high arsenic exposure via drinking water span from Bangladesh, Chile, and Taiwan to the United States. The U.S. Environmental Protection Agency maximum contaminant level (MCL) in drinking water is 10 µg/L; however, concentrations of > 3,000 µg/L have been found in wells in the United States. In addition, exposure through diet is of growing concern. Knowledge of the scope of arsenic-associated health effects has broadened; arsenic leaves essentially no bodily system untouched. Arsenic is a known carcinogen associated with skin, lung, bladder, kidney, and liver cancer. Dermatological, developmental, neurological, respiratory, cardiovascular, immunological, and endocrine effects are also evident. Most remarkably, early-life exposure may be related to increased risks for several types of cancer and other diseases during adulthood. CONCLUSIONS: These data call for heightened awareness of arsenic-related pathologies in broader contexts than previously perceived. Testing foods and drinking water for arsenic, including individual private wells, should be a top priority to reduce exposure, particularly for pregnant women and children, given the potential for life-long effects of developmental exposure.
B. Petruševski, Saroj Sharma, Kathleen Shordt, Jan C. Schippers et al.
Arsenic in drinking water: not just a problem for Bangladesh D. van Halem, S. A. Bakker, G. L. Amy, and J. C. van Dijk Delft University of Technology, Faculty of Civil Engineering and Geosciences, Stevinweg 1, 2628 CN Delft, The Netherlands UNESCO-IHE, Westvest 7, 2611 AX Delft, The Netherlands Received: 11 December 2008 – Accepted: 15 February 2009 – Published: 26 February 2009 Correspondence to: D. van Halem (d.vanhalem@tudelft.nl) Published by Copernicus Publications on behalf of the Delft University of Technology.
Charles F. Harvey, Christopher H. Swartz, A. B. M. Badruzzaman, Nicole Keon-Blute et al.
High levels of arsenic in well water are causing widespread poisoning in Bangladesh. In a typical aquifer in southern Bangladesh, chemical data imply that arsenic mobilization is associated with recent inflow of carbon. High concentrations of radiocarbon-young methane indicate that young carbon has driven recent biogeochemical processes, and irrigation pumping is sufficient to have drawn water to the depth where dissolved arsenic is at a maximum. The results of field injection of molasses, nitrate, and low-arsenic water show that organic carbon or its degradation products may quickly mobilize arsenic, oxidants may lower arsenic concentrations, and sorption of arsenic is limited by saturation of aquifer materials.
Andrew A. Meharg, Md. Mazibur Rahman
Arsenic contaminated groundwater is used extensively in Bangladesh to irrigate the staple food of the region, paddy rice (Oryza sativa L.). To determine if this irrigation has led to a buildup of arsenic levels in paddy fields, and the consequences for arsenic exposure through rice ingestion, a survey of arsenic levels in paddy soils and rice grain was undertaken. Survey of paddy soils throughout Bangladesh showed that arsenic levels were elevated in zones where arsenic in groundwater used for irrigation was high, and where these tube-wells have been in operation for the longest period of time. Regression of soil arsenic levels with tube-well age was significant. Arsenic levels reached 46 microg g(-1) dry weight in the most affected zone, compared to levels below l0 microg g(-1) in areas with low levels of arsenic in the groundwater. Arsenic levels in rice grain from an area of Bangladesh with low levels of arsenic in groundwaters and in paddy soils showed that levels were typical of other regions of the world. Modeling determined, even these typical grain arsenic levels contributed considerably to arsenic ingestion when drinking water contained the elevated quantity of 0.1 mg L(-1). Arsenic levels in rice can be further elevated in rice growing on arsenic contaminated soils, potentially greatly increasing arsenic exposure of the Bangladesh population. Rice grain grown in the regions where arsenic is building up in the soil had high arsenic concentrations, with three rice grain samples having levels above 1.7 microg g(-1).
E. Shaji, M. Santosh, K.V. Sarath, Pranav Prakash et al.
More than 2.5 billion people on the globe rely on groundwater for drinking and providing high-quality drinking water has become one of the major challenges of human society. Although groundwater is considered as safe, high concentrations of heavy metals like arsenic (As) can pose potential human health concerns and hazards. In this paper, we present an overview of the current scenario of arsenic contamination of groundwater in various countries across the globe with an emphasis on the Indian Peninsula. With several newly affected regions reported during the last decade, a significant increase has been observed in the global scenario of arsenic contamination. It is estimated that nearly 108 countries are affected by arsenic contamination in groundwater (with concentration beyond maximum permissible limit of 10 ppb recommended by the World Health Organization. The highest among these are from Asia (32) and Europe (31), followed by regions like Africa (20), North America (11), South America (9) and Australia (4). More than 230 million people worldwide, which include 180 million from Asia, are at risk of arsenic poisoning. Southeast Asian countries, Bangladesh, India, Pakistan, China, Nepal, Vietnam, Burma, Thailand and Cambodia, are the most affected. In India, 20 states and 4 Union Territories have so far been affected by arsenic contamination in groundwater. An attempt to evaluate the correlation between arsenic poisoning and aquifer type shows that the groundwater extracted from unconsolidated sedimentary aquifers, particularly those which are located within the younger orogenic belts of the world, are the worst affected. More than 90% of arsenic pollution is inferred to be geogenic. We infer that alluvial sediments are the major source for arsenic contamination in groundwater and we postulate a strong relation with plate tectonic processes, mountain building, erosion and sedimentation. Prolonged consumption of arsenic-contaminated groundwater results in severe health issues like skin, lung, kidney and bladder cancer; coronary heart disease; bronchiectasis; hyperkeratosis and arsenicosis. Since the major source of arsenic in groundwater is of geogenic origin, the extend of pollution is complexly linked with aquifer geometry and aquifer properties of a region. Therefore, remedial measures are to be designed based on the source mineral, climatological and hydrogeological scenario of the affected region. The corrective measures available include removing arsenic from groundwater using filters, exploring deeper or alternative aquifers, treatment of the aquifer itself, dilution method by artificial recharge to groundwater, conjunctive use, and installation of nano-filter, among other procedures. The vast majority of people affected by arsenic contamination in the Asian countries are the poor who live in rural areas and are not aware of the arsenic poisoning and treatment protocols. Therefore, creating awareness and providing proper medical care to these people remain as a great challenge. Very few policy actions have been taken at international level over the past decade to reduce arsenic contamination in drinking water, with the goal of preventing toxic impacts on human health. We recommend that that United Nations Environment Programme (UNEP) and WHO should take stock of the global arsenic poisoning situation and launch a global drive to create awareness among people/medical professionals/health workers/administrators on this global concern.
J.M. McArthur, Peter Ravenscroft, S. Safiulla, M. F. Thirlwall
In the deltaic plain of the Ganges‐Meghna‐Brahmaputra Rivers, arsenic concentrations in groundwater commonly exceed regulatory limits (>50 µg L −1 ) because FeOOH is microbially reduced and releases its sorbed load of arsenic to groundwater. Neither pyrite oxidation nor competitive exchange with fertilizer phosphate contribute to arsenic pollution. The most intense reduction and so severest pollution is driven by microbial degradation of buried deposits of peat. Concentrations of ammonium up to 23 mg L −1 come from microbial fermentation of buried peat and organic waste in latrines. Concentrations of phosphorus of up to 5 mg L −1 come from the release of sorbed phosphorus when FeOOH is reductively dissolved and from degradation of peat and organic waste from latrines. Calcium and barium in groundwater come from dissolution of detrital (and possibly pedogenic) carbonate, while magnesium is supplied by both carbonate dissolution and weathering of mica. The 87 Sr/ 86 Sr values of dissolved strontium define a two‐component mixing trend between monsoonal rainfall (0.711±0.001) and detrital carbonate (<0.735).
Ujjwal K. Chowdhury, Bhajan Kumar Biswas, Tarit Roy Chowdhury, Gautam Samanta et al.
Nine districts in West Bengal, India, and 42 districts in Bangladesh have arsenic levels in groundwater above the World Health Organization maximum permissible limit of 50 microg/L. The area and population of the 42 districts in Bangladesh and the 9 districts in West Bengal are 92,106 km(2) and 79.9 million and 38,865 km(2) and 42.7 million, respectively. In our preliminary study, we have identified 985 arsenic-affected villages in 69 police stations/blocks of nine arsenic-affected districts in West Bengal. In Bangladesh, we have identified 492 affected villages in 141 police stations/blocks of 42 affected districts. To date, we have collected 10,991 water samples from 42 arsenic-affected districts in Bangladesh for analysis, 58,166 water samples from nine arsenic-affected districts in West Bengal. Of the water samples that we analyzed, 59 and 34%, respectively, contained arsenic levels above 50 microg/L. Thousands of hair, nail, and urine samples from people living in arsenic-affected villages have been analyzed to date; Bangladesh and West Bengal, 93 and 77% samples, on an average, contained arsenic above the normal/toxic level. We surveyed 27 of 42 districts in Bangladesh for arsenic patients; we identified patients with arsenical skin lesions in 25 districts. In West Bengal, we identified patients with lesions in seven of nine districts. We examined people from the affected villages at random for arsenical dermatologic features (11,180 and 29,035 from Bangladesh and West Bengal, respectively); 24.47 and 15.02% of those examined, respectively, had skin lesions. After 10 years of study in West Bengal and 5 in Bangladesh, we feel that we have seen only the tip of iceberg.
Paul N. Williams, Adam H. Price, Andrea Raab, Sk Arafat Hossain et al.
Ingestion of drinking water is not the only elevated source of arsenic to the diet in the Bengal Delta. Even at background levels, the arsenic in rice contributes considerably to arsenic ingestion in subsistence rice diets. We set out to survey As speciation in different rice varieties from different parts of the globe to understand the contribution of rice to arsenic exposure. Pot experiments were utilized to ascertain whether growing rice on As contaminated soil affected speciation and whether genetic variation accounted for uptake and speciation. USA long grain rice had the highest mean arsenic level in the grain at 0.26 microg As g(-1) (n = 7), and the highest grain arsenic value of the survey at 0.40 microg As g(-1). The mean arsenic level of Bangladeshi rice was 0.13 microg As g(-1) (n = 15). The main As species detected in the rice extract were AsIII, DMAV, and AsV. In European, Bangladeshi, and Indian rice 64 +/- 1% (n = 7), 80 +/- 3% (n = 11), and 81 +/- 4% (n = 15), respectively, of the recovered arsenic was found to be inorganic. In contrast, DMAV was the predominant species in rice from the USA, with only 42 +/- 5% (n = 12) of the arsenic being inorganic. Pot experiments show that the proportions of DMAV in the grain are significantly dependent on rice cultivar (p = 0.026) and that plant nutrient status is effected by arsenic exposure.
Andrew A. Meharg, Paul N. Williams, Eureka Adomako, Youssef Y. Lawgali et al.
An extensive data set of total arsenic analysis for 901 polished (white) grain samples, originating from 10 countries from 4 continents, was compiled. The samples represented the baseline (i.e., notspecifically collected from arsenic contaminated areas), and all were for market sale in major conurbations. Median total arsenic contents of rice varied 7-fold, with Egypt (0.04 mg/kg) and India (0.07 mg/kg) having the lowest arsenic content while the U.S. (0.25 mg/kg) and France (0.28 mg/kg) had the highest content. Global distribution of total arsenic in rice was modeled by weighting each country's arsenic distribution by that country's contribution to global production. A subset of 63 samples from Bangladesh, China, India, Italy, and the U.S. was analyzed for arsenic species. The relationship between inorganic arsenic contentversus total arsenic contentsignificantly differed among countries, with Bangladesh and India having the steepest slope in linear regression, and the U.S. having the shallowest slope. Using country-specific rice consumption data, daily intake of inorganic arsenic was estimated and the associated internal cancer risk was calculated using the U.S. Environmental Protection Agency (EPA) cancer slope. Median excess internal cancer risks posed by inorganic arsenic ranged 30-fold for the 5 countries examined, being 0.7 per 10,000 for Italians to 22 per 10,000 for Bangladeshis, when a 60 kg person was considered.
Maria Argos, Tara Kalra, Paul J. Rathouz, Yu Chen et al.
Background Millions of people worldwide are chronically exposed to arsenic through drinking water, including 35–77 million people in Bangladesh. The association between arsenic exposure and mortality rate has not been prospectively investigated by use of individual-level data. We therefore prospectively assessed whether chronic and recent changes in arsenic exposure are associated with all-cause and chronic-disease mortalities in a Bangladeshi population. Methods In the prospective cohort Health Effects of Arsenic Longitudinal Study (HEALS), trained physicians unaware of arsenic exposure interviewed in person and clinically assessed 11 746 population-based participants (aged 18–75 years) from Araihazar, Bangladesh. Participants were recruited from October, 2000, to May, 2002, and followed-up biennially. Data for mortality rates were available throughout February, 2009. We used Cox proportional hazards model to estimate hazard ratios (HRs) of mortality, with adjustment for potential confounders, at different doses of arsenic exposure. Findings 407 deaths were ascertained between October, 2000, and February, 2009. Multivariate adjusted HRs for all-cause mortality in a comparison of arsenic at concentrations of 10·1–50·0 μg/L, 50·1–150·0 μg/L, and 150·1–864·0 μg/L with at least 10·0 μg/L in well water were 1·34 (95% CI 0·99–1·82), 1·09 (0·81–1·47), and 1·68 (1·26–2·23), respectively. Results were similar with daily arsenic dose and total arsenic concentration in urine. Recent change in exposure, measurement of total arsenic concentrations in urine repeated biennially, did not have much effect on the mortality rate. Interpretation Chronic arsenic exposure through drinking water was associated with an increase in the mortality rate. Follow-up data from this cohort will be used to assess the long-term effects of arsenic exposure and how they might be affected by changes in exposure. However, solutions and resources are urgently needed to mitigate the resulting health effects of arsenic exposure. Funding US National Institutes of Health.
C.A.J. Appelo, M. J. J. Van Der Weiden, Christophe Tournassat, Laurent Charlet
Surface complexation models are commonly used to predict the mobility of trace metals in aquifers. For arsenic in groundwater, surface complexation models cannot be used because the database is incomplete. Both carbonate and ferrous iron are often present at a high concentration in groundwater and will influence the sorption of arsenic, but the surface complexation constants are absent in the database of Dzombak and Morel. This paper presents the surface complexation constants for carbonate and ferrous iron on ferrihydrite as derived for the double-layer model. For ferrous iron the constants were obtained from published data supplemented by new experiments to determine the sorption on the strong sites of ferrihydrite. For carbonate the constants were derived from experiments by Zachara et al., who employed relatively low concentrations of carbonate. The double-layer model, optimized for low concentrations, was tested against sorption experiments of carbonate on goethite at higher concentration by Villalobos and Leckie, and reasonable agreement was found. Sorption was also estimated using linear free energy relations (LFER), and results compared well with our derived constants. Model calculations confirm that sorption of particularly carbonate at common soil and groundwater concentrations reduces the sorption capacity of arsenic on ferrihydrite significantly. The displacing effect of carbonate on sorbed arsenate and arsenite has been overlooked in many studies. It may be an important cause for the high concentrations of arsenic in groundwater in Bangladesh. Sediments containing high amounts of sorbed arsenic are deposited in surface water with low carbonate concentrations. Subsequently the sediments become exposed to groundwater with a high dissolved carbonate content, and arsenic is mobilized by displacement from the sediment surface.
Kazi Matin Ahmed, Prosun Bhattacharya, Mahmudul Hasan, S. H. Akhter et al.
Prosun Bhattacharya, Alan H. Welch, Kenneth G. Stollenwerk, Mike J. McLaughlin et al.
Arsenic (As) distribution and toxicology in the environment is a serious issue, with millions of individuals worldwide being affected by As toxicosis. Sources of As contamination are both natural and anthropogenic and the scale of contamination ranges from local to regional. There are many areas of research that are being actively pursued to address the As contamination problem. These include new methods of screening for As in the field, determining the epidemiology of As in humans, and identifying the risk of As uptake in agriculture. Remediation of As-affected water supplies is important and research includes assessing natural remediation potential as well as phytoremediation. Another area of active research is on the microbially mediated biogeochemical interactions of As in the environment. In 2005, a conference was convened to bring together scientists involved in many of the different areas of As research. In this paper, we present a synthesis of the As issues in the light of long-standing research and with regards to the new findings presented at this conference. This contribution provides a backdrop to the issues raised at the conference together with an overview of contemporary and historical issues of As contamination and health impacts.
Joinal Abedin, Malcolm S. Cresser, Andy A. Meharg, Jörg Feldmann et al.
The use of arsenic (As) contaminated groundwater for irrigation of crops has resulted in elevated concentrations of arsenic in agricultural soils in Bangladesh, West Bengal (India), and elsewhere. Paddy rice (Oryza sativa L.) is the main agricultural crop grown in the arsenic-affected areas of Bangladesh. There is, therefore, concern regarding accumulation of arsenic in rice grown those soils. A greenhouse study was conducted to examine the effects of arsenic-contaminated irrigation water on the growth of rice and uptake and speciation of arsenic. Treatments of the greenhouse experiment consisted of two phosphate doses and seven different arsenate concentrations ranging from 0 to 8 mg of As L(-1) applied regularly throughout the 170-day post-transplantation growing period until plants were ready for harvesting. Increasing the concentration of arsenate in irrigation water significantly decreased plant height, grain yield, the number of filled grains, grain weight, and root biomass, while the arsenic concentrations in root, straw, and rice husk increased significantly. Concentrations of arsenic in rice grain did not exceed the food hygiene concentration limit (1.0 mg of As kg(-1) dry weight). The concentrations of arsenic in rice straw (up to 91.8 mg kg(-1) for the highest As treatment) were of the same order of magnitude as root arsenic concentrations (up to 107.5 mg kg(-1)), suggesting that arsenic can be readily translocated to the shoot. While not covered by food hygiene regulations, rice straw is used as cattle feed in many countries including Bangladesh. The high arsenic concentrations may have the potential for adverse health effects on the cattle and an increase of arsenic exposure in humans via the plant-animal-human pathway. Arsenic concentrations in rice plant parts except husk were not affected by application of phosphate. As the concentration of arsenic in the rice grain was low, arsenic speciation was performed only on rice straw to predict the risk associated with feeding contaminated straw to the cattle. Speciation of arsenic in tissues (using HPLC-ICP-MS) revealed that the predominant species present in straw was arsenate followed by arsenite and dimethylarsinic acid (DMAA). As DMAA is only present at low concentrations, it is unlikely this will greatly alter the toxicity of arsenic present in rice.
Dipankar Chakraborti, Subhash Chandra Mukherjee, Shyamapada Pati, Mrinal Kumar Sengupta et al.
The pandemic of arsenic poisoning due to contaminated groundwater in West Bengal, India, and all of Bangladesh has been thought to be limited to the Ganges Delta (the Lower Ganga Plain), despite early survey reports of arsenic contamination in groundwater in the Union Territory of Chandigarh and its surroundings in the northwestern Upper Ganga Plain and recent findings in the Terai area of Nepal. Anecdotal reports of arsenical skin lesions in villagers led us to evaluate arsenic exposure and sequelae in the Semria Ojha Patti village in the Middle Ganga Plain, Bihar, where tube wells replaced dug wells about 20 years ago. Analyses of the arsenic content of 206 tube wells (95% of the total) showed that 56.8% exceeded arsenic concentrations of 50 micro g/L, with 19.9% > 300 micro g/L, the concentration predicting overt arsenical skin lesions. On medical examination of a self-selected sample of 550 (390 adults and 160 children), 13% of the adults and 6.3% of the children had typical skin lesions, an unusually high involvement for children, except in extreme exposures combined with malnutrition. The urine, hair, and nail concentrations of arsenic correlated significantly (r = 0.72-0.77) with drinking water arsenic concentrations up to 1,654 micro g/L. On neurologic examination, arsenic-typical neuropathy was diagnosed in 63% of the adults, a prevalence previously seen only in severe, subacute exposures. We also observed an apparent increase in fetal loss and premature delivery in the women with the highest concentrations of arsenic in their drinking water. The possibility of contaminated groundwater at other sites in the Middle and Upper Ganga Plain merits investigation.
Md. Shiblur Rahaman, Md. Mostafizur Rahman, Nathan Mise, Md. Tajuddin Sikder et al.
Arsenic is a well-recognized environmental contaminant that occurs naturally through geogenic processes in the aquifer. More than 200 million people around the world are potentially exposed to the elevated level of arsenic mostly from Asia and Latin America. Many adverse health effects including skin diseases (i.e., arsenicosis, hyperkeratosis, pigmentation changes), carcinogenesis, and neurological diseases have been reported due to arsenic exposure. In addition, arsenic has recently been shown to contribute to the onset of non-communicable diseases, such as diabetes mellitus and cardiovascular diseases. The mechanisms involved in arsenic-induced diabetes are pancreatic β-cell dysfunction and death, impaired insulin secretion, insulin resistance and reduced cellular glucose transport. Whereas, the most proposed mechanisms of arsenic-induced hypertension are oxidative stress, disruption of nitric oxide signaling, altered vascular response to neurotransmitters and impaired vascular muscle calcium (Ca 2+ ) signaling, damage of renal, and interference with the renin-angiotensin system (RAS). However, the contributions of arsenic exposure to non-communicable diseases are complex and multifaceted, and little information is available about the molecular mechanisms involved in arsenic-induced non-communicable diseases and also no suitable therapeutic target identified yet. Therefore, in the future, more basic research is necessary to identify the appropriate therapeutic target for the treatment and management of arsenic-induced non-communicable diseases. Several reports demonstrated that a daily balanced diet with proper nutrient supplements (vitamins, micronutrients, natural antioxidants) has shown effective to reduce the damages caused by arsenic exposure. Arsenic detoxication through natural compounds or nutraceuticals is considered a cost-effective treatment/management and researchers should focus on these alternative options. This review paper explores the scenarios of arsenic contamination in groundwater with an emphasis on public health concerns. It also demonstrated arsenic sources, biogeochemistry, toxicity mechanisms with therapeutic targets, arsenic exposure-related human diseases, and onsets of cardiovascular diseases as well as feasible management options for arsenic toxicity.
Paul N. Williams, Md. Rafiqul Islam, Eureka Adomako, Andrea Raab et al.
Concern has been raised by Bangladeshi and international scientists about elevated levels of arsenic in Bengali food, particularly in rice grain. This is the first inclusive food market-basket survey from Bangladesh, which addresses the speciation and concentration of arsenic in rice, vegetables, pulses, and spices. Three hundred thirty aman and boro rice, 94 vegetables, and 50 pulse and spice samples were analyzed for total arsenic, using inductivity coupled plasma mass spectrometry (ICP-MS). The districts with the highest mean arsenic rice grain levels were all from southwestern Bangladesh: Faridpur (boro) 0.51 > Satkhira (boro) 0.38 > Satkhira (aman) 0.36 > Chuadanga (boro) 0.32 > Meherpur (boro) 0.29 microg As g(-1). The vast majority of food ingested arsenic in Bangladesh diets was found to be inorganic; with the predominant species detected in Bangladesh rice being arsenite (AsIII) or arsenate (AsV) with dimethyl arsinic acid (DMAV) being a minor component. Vegetables, pulses, and spices are less important to total arsenic intake than water and rice. Predicted inorganic arsenic intake from rice is modeled with the equivalent intake from drinking water for a typical Bangladesh diet. Daily consumption of rice with a total arsenic level of 0.08 microg As g(-1) would be equivalent to a drinking water arsenic level of 10 microg L(-1).