| 1. |
- Bhattacharya, Prosun, et al.
(författare)
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Temporal and seasonal variability of arsenic in drinking water wells in Matlab, southeastern Bangladesh : A preliminary evaluation on the basis of a 4 year study
- 2011
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Ingår i: Journal of Environmental Science and Health. Part A. - : Informa UK Limited. - 1093-4529 .- 1532-4117. ; 46:11, s. 1177-1184
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Tidskriftsartikel (refereegranskat)abstract
- Temporal and seasonal variability of As concentrations in groundwater were evaluated in As-affected areas of Matlab, southeastern Bangladesh. Groundwater samples from 61 randomly selected tubewells were analyzed for As concentrations over a period of three years and four months (from July 2002 to November 2005) and monitored seasonally (three times a year). The mean As concentrations in the sampled tubewells decreased from 153 to 123 mu g/L during July 2002 to November 2005. Such changes were pronounced in tubewells with As concentration >50 mu g/L than those with As concentrations <50 mu g/L. Similarly, individual wells revealed temporal variability, for example some wells indicated a decreasing trend, while some other wells indicated stable As concentration during the monitoring period. The mean As concentrations were significantly higher in Matlab North compared with Matlab South. The spatial variations in the mean As concentrations may be due to the differences in local geological conditions and groundwater flow patterns. The variations in mean As concentrations were also observed in shallow (<40 m) and deep (>40 m) wells. However, to adequately evaluate temporal and seasonal variability of As concentration, it is imperative to monitor As concentrations in tubewells over a longer period of time. Such long-term monitoring will provide important information for the assessment of human health risk and the sustainability of safe drinking water supplies.
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| 2. |
- Sohel, Nazmul, 1962-, et al.
(författare)
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Spatial patterns of fetal loss and infant death in an arsenic-affected area in Bangladesh
- 2010
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Ingår i: International Journal of Health Geographics. - 1476-072X. ; 9, s. 53-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Arsenic exposure in pregnancy is associated with adverse pregnancy outcome and infant mortality. Knowledge of the spatial characteristics of the outcomes and their possible link to arsenic exposure are important for planning effective mitigation activities. The aim of this study was to identify spatial and spatiotemporal clustering of fetal loss and infant death, and spatial relationships between high and low clusters of fetal loss and infant death rates and high and low clusters of arsenic concentrations in tube-well water used for drinking.Methods: Pregnant women from Matlab, Bangladesh, who used tube-well water for drinking while pregnant between 1991 and 2000, were included in this study. In total 29,134 pregnancies were identified. A spatial scan test was used to identify unique non-random spatial and spatiotemporal clusters of fetal loss and infant death using a retrospective spatial and spatiotemporal permutation and Poisson probability models.Results: Two significant clusters of fetal loss and infant death were identified and these clusters remained stable after adjustment for covariates. One cluster of higher rates of fetal loss and infant death was in the vicinity of the Meghna River, and the other cluster of lower rates was in the center of Matlab. The average concentration of arsenic in the water differed between these clusters (319 μg/L for the high cluster and 174 μg/L for the low cluster). The spatial patterns of arsenic concentrations in tube-well water were found to be linked with the adverse pregnancy outcome clusters. In the spatiotemporal analysis, only one high fetal loss and infant death cluster was identified in the same high cluster area obtained from purely spatial analysis. However, the cluster was no longer significant after adjustment for the covariates.Conclusion: The finding of this study suggests that given the geographical variation in tube-well water contamination, higher fetal loss and infant deaths were observed in the areas of higher arsenic concentrations in groundwater. This illustrates a possible link between arsenic contamination in tube-well water and adverse pregnancy outcome. Thus, these areas should be considered a priority in arsenic mitigation programs.
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| 3. |
- Lindberg, Anna-Lena, et al.
(författare)
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Impact of smoking and chewing tobacco on arsenic-induced skin lesions
- 2010
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Ingår i: Journal of Environmental Health Perspectives. - : Environmental Health Perspectives. - 0091-6765 .- 1552-9924. ; 118:4, s. 533-538
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: We recently reported that the main reason for the documented higher prevalence of arsenic-related skin lesions among men than among women is the result of less efficient arsenic metabolism. OBJECTIVE: Because smoking has been associated with less efficient arsenic methylation, we aimed to elucidate interactions between tobacco use and arsenic metabolism for the risk of developing skin lesions. METHODS: We used a population-based case-referent study that showed increased risk for skin lesions in relation to chronic arsenic exposure via drinking water in Bangladesh and randomly selected 526 of the referents (random sample of inhabitants > 4 years old; 47% male) and all 504 cases (54% male) with arsenic-related skin lesions to measure arsenic metabolites [methylarsonic acid (MA) and dimethylarsinic acid (DMA)] in urine using high-performance liquid chromatography (HPLC) and inductively coupled plasma mass spectrometry (ICPMS). RESULTS: The odds ratio for skin lesions was almost three times higher in the highest tertile of urinary %MA than in the lowest tertile. Men who smoked cigarettes and bidis (locally produced cigarettes; 33% of referents, 58% of cases) had a significantly higher risk for skin lesions than did nonsmoking men; this association decreased slightly after accounting for arsenic metabolism. Only two women smoked, but women who chewed tobacco (21% of referents, 43% of cases) had a considerably higher risk of skin lesions than did women who did not use tobacco. The odds ratio (OR) for women who chewed tobacco and who had < or = 7.9%MA was 3.8 [95% confidence interval (CI), 1.4-10] compared with women in the same MA tertile who did not use tobacco. In the highest tertile of %MA or %inorganic arsenic (iAs), women who chewed tobacco had ORs of 7.3 and 7.5, respectively, compared with women in the lowest tertiles who did not use tobacco. CONCLUSION: The increased risk of arsenic-related skin lesions in male smokers compared with nonsmokers appears to be partly explained by impaired arsenic methylation, while there seemed to be an excess risk due to interaction between chewing tobacco and arsenic metabolism in women.
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| 4. |
- Sohel, Nazmul, 1962-, et al.
(författare)
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Spatial modelling of individual arsenic exposure via well water : Evaluation of arsenic in urine, main water source and influence of neighbourhood water sources in rural Bangladesh
- 2010
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Ingår i: Journal of Environmental Monitoring. - 1464-0325 .- 1464-0333. ; 12:6, s. 1341-1348
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Tidskriftsartikel (refereegranskat)abstract
- Arsenic concentrations in well water often vary even within limited geographic areas. This makes it difficult to obtain valid estimates of the actual exposure, as people may take their drinking water from different wells. We evaluated a spatial model for estimation of the influence of multiple neighbourhood water sources on the actual exposure, as assessed by concentrations in urine in a population in rural Bangladesh. In total 1,307 individuals were randomly selected. Arsenic concentrations of urine and water were analysed. Simple average and inverse distance weighted average of arsenic concentrations in the five nearest water sources were calculated for each individual. Spatial autocorrelation was evaluated using Moran’s I statistics, and spatial regression models were employed to account for spatial autocorrelation. The average distance from a household to the nearest tube-well was 32 meters (Inter Quartile Range 1-49 meters). Water arsenic concentrations of the reported main water sources were significantly correlated with concentrations in urine (R2=0.41, ρ< 0.0001, R2 for women=0.45 and for men=0.36). General model fit improved only slightly after spatial adjustment for neighbouring water sources (pseudo R2=0.53, spatial lag model), compared to covariate adjusted regression coefficient (R2=0.46). Arsenic concentration in urine was higher than arsenic in main water source with an intercept of 57µg/L, indicating exposure from food. A suitable way of estimating an individual’s past exposure to arsenic in this rural setting, where influence of neighbouring water sources was minimal, was to consider the reported main source of drinking water.
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