Department of Earth and Environmental Studies , Montclair State University , Montclair , New Jersey , United States.
Department of Geology , University of Dhaka , Dhaka , Bangladesh.
Environ Sci Technol. 2019 May 21;53(10):5596-5604. doi: 10.1021/acs.est.9b01375. Epub 2019 May 7.
About 20 million rural Bangladeshis continue to drink well water containing >50 μg/L arsenic (As). This analysis argues for reprioritizing interventions on the basis of a survey of wells serving a population of 380,000 conducted one decade after a previous round of testing overseen by the government. The available data indicate that testing alone reduced the exposed population in the area in the short term by about 130,000 by identifying the subset of low As wells that could be shared at a total cost of <US$1 per person whose exposure was reduced. Testing also had a longer term impact, as 60,000 exposed inhabitants lowered their exposure by installing new wells to tap intermediate (45-90 m) aquifers that are low in As at their own expense of US$30 per person whose exposure was reduced. In contrast, the installation of over 900 deep (>150 m) wells and a single piped-water supply system by the government reduced exposure of little more than 7000 inhabitants at a cost of US$150 per person whose exposure was reduced. The findings make a strong case for long-term funding of free well testing on a massive scale with piped water or groundwater treatment only as a last resort.
约 2000 万孟加拉农村居民仍在饮用砷含量超过 50μg/L 的井水。本分析基于一项针对 38 万人的水井调查，对十年前政府监督的上一轮检测进行了重新评估。现有数据表明，仅通过检测就可以确定哪些低砷水井可以共用，其总成本为每人 1 美元以下，从而在短期内将该地区的暴露人口减少了约 13 万人。检测还产生了长期影响，因为有 6 万名暴露于高砷环境的居民通过安装新井，利用砷含量较低的中间（45-90 米）含水层，自行承担每人 30 美元的费用，将其暴露水平降低。相比之下，政府安装了 900 多口深井（>150 米）和一个单一的管道供水系统，仅将 7000 多名居民的暴露水平降低了，其成本为每人 150 美元。这些发现强烈呼吁长期为大规模免费水井检测提供资金，只有在万不得已的情况下才采用管道水或地下水处理作为最后手段。
