One Solution to the Arsenic Problem: A Return to Surface (Improved Dug) Wells

Arsenic contamination in drinking-water in Bangladesh is a major catastrophe, the consequences of which exceed most other man-made disasters. The national policy encourages the use of surface water as much as possible without encountering the problems of sanitation that led to the use of groundwater in the first place. This paper describes the success of the Dhaka Community Hospital (DCH) team and the procedure in implementing sanitary, arsenic-free, dugwells. The capital cost for running water is US$ 5-6 per person. Sixty-six sanitary dugwells were installed in phases between 2000 and 2004 in Pabna district of Bangladesh where there was a great need of safe water because, in some villages, 90% of tubewells were highly contaminated with arsenic. In total, 1,549 families now have access to safe arsenic-free dugwell water. Some of them have a water-pipe up to their kitchen. All of these were implemented with active participation of community members. They also pay for water-use and are themselves responsible for the maintenance and water quality. The DCH helped the community with installation and maintenance protocol and also with monitoring water quality. The bacteria levels are low but not always zero, and studies are in progress to reduce bacteria by chlorination.Physic

One Solution to the Arsenic Problem: A Return to Surface (Improved Dug) Wells

Arsenic contamination in drinking-water in Bangladesh is a major catastrophe, the consequences of which exceed most other man-made disasters. The national policy encourages the use of surface water as much as possible without encountering the problems of sanitation that led to the use of groundwater in the first place. This paper describes the success of the Dhaka Community Hospital (DCH) team and the procedure in implementing sanitary, arsenic-free, dugwells. The capital cost for running water is US$ 5–6 per person. Sixty-six sanitary dugwells were installed in phases between 2000 and 2004 in Pabna district of Bangladesh where there was a great need of safe water because, in some villages, 90% of tubewells were highly contaminated with arsenic. In total, 1,549 families now have access to safe arsenic-free dugwell water. Some of them have a water-pipe up to their kitchen. All of these were implemented with active participation of community members. They also pay for water-use and are themselves responsible for the maintenance and water quality. The DCH helped the community with installation and maintenance protocol and also with monitoring water quality. The bacteria levels are low but not always zero, and studies are in progress to reduce bacteria by chlorination

Prenatal Arsenic Exposure and DNA Methylation in Maternal and Umbilical Cord Blood Leukocytes

Background: Arsenic is an epigenetic toxicant and could influence fetal developmental programming. Objectives: We evaluated the association between arsenic exposure and DNA methylation in maternal and umbilical cord leukocytes. Methods: Drinking-water and urine samples were collected when women were at ≤ 28 weeks gestation; the samples were analyzed for arsenic using inductively coupled plasma mass spectrometry. DNA methylation at CpG sites in p16 (n = 7) and p53 (n = 4), and in LINE-1 and Alu repetitive elements (3 CpG sites in each), was quantified using pyrosequencing in 113 pairs of maternal and umbilical blood samples. We used general linear models to evaluate the relationship between DNA methylation and tertiles of arsenic exposure. Results: Mean (± SD) drinking-water arsenic concentration was 14.8 ± 36.2 μg/L (range: < 1–230 μg/L). Methylation in LINE-1 increased by 1.36% [95% confidence interval (CI): 0.52, 2.21%] and 1.08% (95% CI: 0.07, 2.10%) in umbilical cord and maternal leukocytes, respectively, in association with the highest versus lowest tertile of total urinary arsenic per gram creatinine. Arsenic exposure was also associated with higher methylation of some of the tested CpG sites in the promoter region of p16 in umbilical cord and maternal leukocytes. No associations were observed for Alu or p53 methylation. Conclusions: Exposure to higher levels of arsenic was positively associated with DNA methylation in LINE-1 repeated elements, and to a lesser degree at CpG sites within the promoter region of the tumor suppressor gene :p16. Associations were observed in both maternal and fetal leukocytes. Future research is needed to confirm these results and determine if these small increases in methylation are associated with any health effects

Variability in Biomarkers of Arsenic Exposure and Metabolism in Adults over Time

Background: Urinary arsenic metabolites (UAs) are used as biomarkers of exposure and metabolism. Ojectives: To characterize inter- and intraindividual variability in UAs in healthy individuals. Methods: In a longitudinal study conducted in Bangladesh, we collected water and spot urine samples from 196 participants every 3 months for 2 years. Water arsenic (As) was measured by inductively coupled plasma-mass spectrometry and urinary As [arsenite, arsenate, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA)] were detected using high-performance liquid chromatography-hydride-generated atomic absorption spectrometry. We used linear mixed-effects models to compute variance components and evaluate the association between UAs and selected factors. Results: The concentrations of UAs were fairly reproducible within individuals, with intraclass correlation coefficients (ICCs) of 0.41, 0.35, 0.47, and 0.49 for inorganic As (InAs), MMA, DMA, and total urinary As (TUA). However, when expressed as a ratio, the percent InAs (%InAs), %MMA, and %DMA were poorly reproducible within individuals, with ICCs of 0.16, 0.16, and 0.17, respectively. Arsenic metabolism was significantly associated with sex, exposure, age, smoking, chewing betel nut, urinary creatinine, and season. Specificity and sensitivity analyses showed that a single urine sample adequately classified a participant's urinary As profile as high or low, but TUA had only moderate specificity for correctly classifying drinking water exposures. Conclusions: Epidemiologic studies should use both urinary As concentrations and the relative proportion of UAs to minimize measurement error and to facilitate interpretation of factors that influence As metabolism

Arsenic Methylation, GSTT1, GSTM1, GSTP1 Polymorphisms, and Skin Lesions

OBJECTIVE: We investigated whether primary and secondary arsenic methylation ratios were associated with skin lesions and whether GSTT1, GSTP1, and GSTM1 polymorphisms modify these relationships. METHODS: A case–control study of 600 cases and 600 controls that were frequency matched on age and sex was conducted in Pabna, Bangladesh, in 2001–2002. Individual well water, urine, and blood samples were collected. Water arsenic concentration was determined using inductively coupled plasma mass spectrometry (ICP-MS). Urinary arsenic speciation was determined using high performance liquid chromatography hydride with generator atomic absorption spectrometry and ICP-MS. Genotyping was conducted using multiplex polymerase chain reaction and TaqMan. RESULTS: A 10-fold increase in primary methylation ratio [monomethylarsonic acid (MMA)/(arsenite + arsenate] was associated with a 1.50-fold increased risk of skin lesions (multivariate odds ratio = 1.50; 95% confidence interval, 1.00–2.26). We observed significant interaction on the multiplicative scale between GSTT1 wildtype and secondary methylation ratio [dimethylarsinic acid/MMA; likelihood ratio test (LRT), p = 0.01]. No significant interactions were observed for GSTM1 or GSTP1 or for primary methylation ratios. CONCLUSION: Our findings suggest that increasing primary methylation ratios are associated with an increase in risk of arsenic-related skin lesions. The interaction between GSTT1 wildtype and secondary methylation ratio modifies risk of skin lesions among arsenic-exposed individuals

Contaminated Turmeric Is a Potential Source of Lead Exposure for Children in Rural Bangladesh

Background. During the conduct of a cohort study intended to study the associations between mixed metal exposures and child health outcomes, we found that 78% of 309 children aged 20–40 months evaluated in the Munshiganj District of Bangladesh had blood lead concentrations ≥5 µg/dL and 27% had concentrations ≥10 µg/dL. Hypothesis. Environmental sources such as spices (e.g., turmeric, which has already faced recalls in Bangladesh due to high lead levels) may be a potential route of lead exposure. Methods. We conducted visits to the homes of 28 children randomly selected from among high and low blood lead concentration groups. During the visits, we administered a structured questionnaire and obtained soil, dust, rice, and spice samples. We obtained water samples from community water sources, as well as environmental samples from neighborhood businesses. Results. Lead concentrations in many turmeric samples were elevated, with lead concentrations as high as 483 ppm. Analyses showed high bioaccessibility of lead. Conclusions. Contamination of turmeric powder is a potentially important source of lead exposure in this population

The Impact of Diet and Betel Nut Use on Skin Lesions Associated with Drinking-Water Arsenic in Pabna, Bangladesh

An established exposure–response relationship exists between water arsenic levels and skin lesions. Results of previous studies with limited historical exposure data, and laboratory animal studies suggest that diet may modify arsenic metabolism and toxicity. In this study, we evaluated the effect of diet on the risk of arsenic-related skin lesions in Pabna, Bangladesh. Six hundred cases and 600 controls loosely matched on age and sex were enrolled at Dhaka Community Hospital, Bangladesh, in 2001–2002. Diet, demographic data, and water samples were collected. Water samples were analyzed for arsenic using inductively coupled plasma mass spectroscopy. Betel nut use was associated with a greater risk of skin lesions in a multivariate model [odds ratio (OR) = 1.67; 95% confidence interval (CI), 1.18–2.36]. Modest decreases in risk of skin lesions were associated with fruit intake 1–3 times/month (OR = 0.68; 95%CI, 0.51–0.89) and canned goods at least 1 time/month (OR = 0.41; 95% CI, 0.20–0.86). Bean intake at least 1 time/day (OR = 1.89; 95% CI, 1.11–3.22) was associated with increased odds of skin lesions. Betel nut use appears to be associated with increased risk of developing skin lesions in Bangladesh. Increased intake of fruit and canned goods may be associated with reduced risk of lesions. Increased intake of beans may be associated with an increased risk of skin lesions. The results of this study do not provide clear support for a protective effect of vegetable and overall protein consumption against the development of skin lesions, but a modest benefit cannot be excluded

Genetic Susceptible Locus in NOTCH2 Interacts with Arsenic in Drinking Water on Risk of Type 2 Diabetes

Abstract: Background: Chronic exposure to arsenic in drinking water is associated with increased risk of type 2 diabetes mellitus (T2DM) but the underlying molecular mechanism remains unclear. Objectives: This study evaluated the interaction between single nucleotide polymorphisms (SNPs) in genes associated with diabetes and arsenic exposure in drinking water on the risk of developing T2DM. Methods: In 2009-2011, we conducted a follow up study of 957 Bangladeshi adults who participated in a case-control study of arsenic-induced skin lesions in 2001-2003. Logistic regression models were used to evaluate the association between 38 SNPs in 18 genes and risk of T2DM measured at follow up. T2DM was defined as having a blood hemoglobin A1C level greater than or equal to 6.5% at follow-up. Arsenic exposure was characterized by drinking water samples collected from participants' tubewells. False discovery rates were applied in the analysis to control for multiple comparisons. Results: Median arsenic levels in 2001-2003 were higher among diabetic participants compared with non-diabetic ones (71.6 mu g/L vs. 12.5 mu g/L, p-value <0.001). Three SNPs in ADAMTS9 were nominally associated with increased risk of T2DM (rs17070905, Odds Ratio (OR) = 2.30, 95% confidence interval (CI) 1.17-4.50; rs17070967, OR = 2.02, 95% CI 1.00-4.06; rs6766801, OR = 2.33, 95% CI 1.18-4.60), but these associations did not reach the statistical significance after adjusting for multiple comparisons. A significant interaction between arsenic and NOTCH2 (rs699780) was observed which significantly increased the risk of T2DM (p for interaction = 0.003; q-value = 0.021). Further restricted analysis among participants exposed to water arsenic of less than 148 mu g/L showed consistent results for interaction between the NOTCH2 variant and arsenic exposure on T2DM (p for interaction = 0.048; q-value = 0.004)