619 research outputs found

    Reducing poisoning by arsenic in tubewell water

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    Rwanda must create an additional 200,000 jobs per year to absorb its expanding population. Increasing exports could play an important role in achieving this goal. A new policy brief by the IGC outlines the challenges Rwanda needs to overcome to improve its trade balances

    Comparison of dissolved and particulate arsenic distributions in shallow aquifers of Chakdaha, India, and Araihazar, Bangladesh

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    International audienceBackground The origin of the spatial variability of dissolved As concentrations in shallow aquifers of the Bengal Basin remains poorly understood. To address this, we compare here transects of simultaneously-collected groundwater and aquifer solids perpendicular to the banks of the Hooghly River in Chakdaha, India, and the Old Brahmaputra River in Araihazar, Bangladesh. Results Variations in surface geomorphology mapped by electromagnetic conductivity indicate that permeable sandy soils are associated with underlying aquifers that are moderately reducing to a depth of 10–30 m, as indicated by acid-leachable Fe(II)/Fe ratios 5 mg L-1. More reducing aquifers are typically capped with finer-grained soils. The patterns suggest that vertical recharge through permeable soils is associated with a flux of oxidants on the banks of the Hooghly River and, further inland, in both Chakdaha and Araihazar. Moderately reducing conditions maintained by local recharge are generally associated with low As concentrations in Araihazar, but not systematically so in Chakdaha. Unlike Araihazar, there is also little correspondence in Chakdaha between dissolved As concentrations in groundwater and the P-extractable As content of aquifer particles, averaging 191 ± 122 ug As/L, 1.1 ± 1.5 mg As kg-1 (n = 43) and 108 ± 31 ug As/L, 3.1 ± 6.5 mg As kg-1 (n = 60), respectively. We tentatively attribute these differences to a combination of younger floodplain sediments, and therefore possibly more than one mechanism of As release, as well as less reducing conditions in Chakdaha compared to Araihazar. Conclusion Systematic dating of groundwater and sediment, combined with detailed mapping of the composition of aquifer solids and groundwater, will be needed to identify the various mechanisms underlying the complex distribution of As in aquifers of the Bengal Basin

    Water Arsenic Exposure and Intellectual Function in 6-Year-Old Children in Araihazar, Bangladesh

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    BACKGROUND: We recently reported results of a cross-sectional investigation of intellectual function in 10-year-olds in Bangladesh, who had been exposed to arsenic from drinking water in their home wells. OBJECTIVES: We present results of a similar investigation of 301 randomly selected 6-year-olds whose parents participated in our ongoing prospective study of the health effects of As exposure in 12,000 residents of Araihazar, Bangladesh. METHODS: Water As and manganese concentrations of tube wells at each home were obtained by surveying all study region wells. Children and mothers were first visited at home, where the quality of home stimulation was measured, and then seen in our field clinic, where children received a medical examination wherein weight, height, and head circumference were assessed. We assessed children’s intellectual function using subtests drawn from the Wechsler Preschool and Primary Scale of Intelligence, version III, by summing weighted items across domains to create Verbal, Performance, Processing Speed, and Full-Scale raw scores. Children provided urine specimens for measuring urinary As and were asked to provide blood samples for blood lead measurements. RESULTS: Exposure to As from drinking water was associated with reduced intellectual function before and after adjusting for water Mn, for blood lead levels, and for sociodemographic features known to contribute to intellectual function. With covariate adjustment, water As remained significantly negatively associated with both Performance and Processing Speed raw scores; associations were less strong than in our previously studied 10-year-olds. CONCLUSION: This second cross-sectional study of As exposure expands our concerns about As neurotoxicity to a younger age group

    Trace metal sources for the Atlantic inflow to the Mediterranean Sea

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Ocean Engineering, 1989.Vita.Includes bibliographical references.by Alexander F.M.J. van Geen.Ph.D

    Prevalence of Arsenic Exposure from Drinking Water and Awareness of Its Health Risks in a Bangladeshi Population: Results from a Large Population-Based Study

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    We conducted a population-based prevalence survey in Araihazar, Bangladesh, to describe the distribution of arsenic exposure in a rural Bangladeshi population and to assess the population’s awareness to this problem as well as to possible remediation options. Water samples from 5,967 contiguous tube wells in a defined geographic area were tested using laboratory-based methods. Additionally, for each well, the owner/caretaker (or a close relative) was interviewed regarding his or her awareness of the health consequences of As exposure. Arsenic exposure data and demographic characteristics for the 65,876 users of these wells were also collected from the 5,967 respondents. Among the 65,876 residents, more than half (54%) regularly consumed well water with an As concentration ≄ 50 ÎŒg/L—above the acceptable government standard in Bangladesh. Respondents were 15–92 years of age, with an average age of 42 years, and 43% were male. Presence of awareness was significantly related to male sex, nonlabor head of household occupation, better housing, and having had the well tested for As concentration. Most respondents (92%) expressed a willingness to take steps to reduce their exposure, with switching to a safe well the most favored option (46.2%). Willingness to reduce exposure was positively related to awareness of the health risks of As. However, the association between awareness and switching to a safe well [odds ratio (OR) = 1.25; 95% confidence interval (CI), 1.01–1.54] was no stronger than the associations between awareness and using surface water (with or without treatments) (OR = 1.54; 95% CI, 1.22–1.95) or using an existing well after treatment or increasing the depth (OR = 1.34; 95% CI, 1.08–1.67). These findings suggest that health education programs may need to target individuals with lower socioeconomic status and that well switching should be encouraged with more appropriate health education. Increasing knowledge of the health consequences of As may be an important element in facilitating remediation

    Targeting Low-arsenic Groundwater with Mobile-phone Technology in Araihazar, Bangladesh

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    The Bangladesh Arsenic Mitigation and Water Supply Program (BAMWSP) has compiled field-kit measurements of the arsenic content of groundwater for nearly five million wells. By comparing the spatial distribution of arsenic inferred from these field-kit measurements with geo-referenced laboratory data in a portion of Araihazar upazila, it is shown here that the BAMWSP data could be used for targeting safe aquifers for the installation of community wells in many villages of Bangladesh. Recent experiences with mobile-phone technology to access and update the BAMWSP data in the field are also described. It is shown that the technology, without guaranteeing success, could optimize interventions by guiding the choice of the drilling method that is likely to reach a safe aquifer and identifying those villages where exploratory drilling is needed
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