Department of Geology and Mining, University of Rajshahi, Rajshahi 6205, Bangladesh.
Institute of National Analytical Research and Service (INARS), Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhanmondi, Dhaka 1205, Bangladesh.
Chemosphere. 2022 May;294:133556. doi: 10.1016/j.chemosphere.2022.133556. Epub 2022 Jan 7.
To understand the mechanistic pathway of arsenic (As) enrichment and mobilization in groundwater (southeastern Bangladesh) and to evaluate the water quality as well as associated health risks, a suite of systematically collected groundwater samples (depth: 17-61 m) were analyzed. Arsenic concentrations (μg L) in the groundwater samples were ranged from 6 to 581 with a mean value of 199 which is significantly higher than the recommended values. The assessment of water quality using entropy water quality index and irrigation water quality indices revealed that the groundwater in the studied region was not recommended for drinking and irrigation, respectively with few exceptions. Dominant water types in the studied area were Ca-Mg-HCO Na-HCO, and Na-Cl types. Various forms of water-rock interactions, leaching of evaporates, and the confined nature of the aquifer mostly control the hydro-chemical parameters. Fe/Mn bound As are likely to be released in the aquifer through the dissolution of carbonate minerals of Fe/Mn while the higher degree of water-rock interaction and probable oxidation of organic materials helped to elevate As concentration. The probable longer residence time of groundwater guided by topographic slope and the neighboring clayey aquitard govern the As mobilization in the aquifer. Probabilistic health risk assessment revealed that groundwaters from the studied area can cause both non-carcinogenic and carcinogenic health risks.
为了了解砷（As）在地下水（孟加拉东南部）中的富集和迁移的机制途径，并评估水质以及相关的健康风险，我们系统地采集了一系列地下水样本（深度：17-61 米）进行分析。地下水样本中的砷浓度（μg/L）范围为 6 至 581，平均值为 199，明显高于推荐值。使用熵水质指数和灌溉水质指数评估水质表明，研究区域的地下水不适合饮用和灌溉，除了少数例外。研究区主要的水类型为 Ca-Mg-HCO3、Na-HCO3 和 Na-Cl 型。各种形式的水岩相互作用、蒸发盐的淋滤以及含水层的封闭性质主要控制着水化学参数。Fe/Mn 结合态的 As 可能通过碳酸盐矿物的溶解而在含水层中释放，而较高程度的水岩相互作用和可能的有机物质氧化有助于提高 As 浓度。地形坡度和邻近的粘土层所引导的地下水可能具有更长的滞留时间，从而控制了含水层中 As 的迁移。概率健康风险评估表明，研究区域的地下水可能会导致非致癌和致癌健康风险。
