Mechanisms of Natural Arsenic-Pollution of Groundwater

天然砷污染地下水的机制

• 批准号: NE/H009574/1
• 负责人: John McArthur
• 金额: $ 37.38万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2011
• 资助国家: 英国
• 起止时间: 2011 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FH009574%2F1
• 关键词: Mechanisms; Natural; Arsenic; Pollution; Groundwater

Sediments laid down by rivers (termed alluvial sediments) form important aquifers worldwide. Groundwater from such alluvial aquifers across the World provides much of the world's water supply. Since 1995, As-pollution of groundwater has been discovered in around 30 deltaic and coastal aquifers worldwide and in many other inland alluvial basins of the World. The problem is particularly severe in SE Asia, especially West Bengal and Bangladesh. The consequence for human health has been immense. Arsenic-polluted groundwater contains As in concentrations greater than the World Health Organization's Guideline Value for drinking water of 10 microgrammes per litre As. Arsenic is odourless, tasteless, poisonous, and a carcinogen with a long period of latency (tens of years). This long latency period for many years postponed recognition of the adverse affects of As in groundwater on human health. That impact is now known to be severe and global in extent: the effects of the consumption of As-rich groundwater in Bangladesh alone was termed 'the worst mass poisoning of a population in history' by Allan Smith, an epidemiologist at the University of California, Berkley, who predicted that, by 2010, one in ten deaths in that country might be As-related unless effective remediation was rapidly undertaken. If As-pollution is to be dealt with effectively, the mechanism of pollution must be revealed in detail. Until we understand that process, strategies for aquifer remediation and development will not be based on sound science. Because process in groundwater are generic, and not site specific, many of the scientists who are aware of, and seek to understand, the process of arsenic pollution in groundwater accept that arsenic is released into groundwater as a by-product of the microbial metabolism of decaying plant material in the sediments of the region. Beyond that general agreement, opinions differ as to how the arsenic is released into the groundwater. In particular, the identities of the microbes that may be responsible for driving the process, and the details of how they do so, are all but unknown. This project seeks to identify the bacteria responsible for the process of As-pollution, discover the details of that process or processes, and show how the distribution of relevant bacterial markers for As-mobilization in aquifer sediments are related to the distribution of arsenic pollution. Whatever proves to be the precise mechanism or mechanisms driving As-pollution in the Bengal Basin is likely to have a worldwide application, so our work will provide a framework within which to understand the cause(s) of pollution in most alluvial aquifers worldwide. The understanding of mechanism will underpin the choice made by policy makers regarding development and avoidance strategies for such aquifers across the world. Such information will be valuable to all those involved in water-quality monitoring and health surveys. The knowledge we gain may change future approaches to As research, aquifer development, and aquifer remediation.

河流沉积的沉积物（称为冲积沉积物）形成了世界各地重要的含水层。来自世界各地这种冲积含水层的地下水提供了世界上大部分的供水。自1995年以来，在全球约30个三角洲和沿海含水层以及许多内陆冲积盆地中发现了地下水砷污染。这个问题在东南亚尤其严重，尤其是西孟加拉和孟加拉国。对人类健康的影响是巨大的。受砷污染的地下水所含砷的浓度高于世界卫生组织的饮用水指导值每升10微克砷。砷无臭、无味、有毒，是一种潜伏期很长（数十年）的致癌物质。这一漫长的潜伏期，多年推迟认识到地下水中的砷对人体健康的不利影响。现在人们知道，这种影响是严重的，而且是全球性的：仅在孟加拉国消费富含砷的地下水的影响就被加州大学伯克利分校的流行病学家Allan Smith称为“历史上最严重的人口大规模中毒”，他预测，到2010年，如果不迅速采取有效的补救措施，该国十分之一的死亡可能与砷有关。要有效地治理砷污染，必须详细揭示砷污染的机理。在我们了解这一过程之前，含水层补救和开发战略将不会以可靠的科学为基础。由于地下水中的过程是通用的，而不是特定的地点，许多了解并试图了解地下水中砷污染过程的科学家都认为砷是作为该地区沉积物中腐烂植物材料的微生物代谢的副产品释放到地下水中的。除了这一普遍共识之外，关于砷是如何释放到地下水中的，人们的看法也各不相同。特别是，可能负责驱动这一过程的微生物的身份，以及它们如何做到这一点的细节，几乎都是未知的。该项目旨在确定细菌负责的过程中的砷污染，发现该过程或过程的细节，并显示如何在含水层沉积物中的砷动员相关的细菌标志物的分布与砷污染的分布。无论被证明是精确的机制或机制驱动作为污染在孟加拉盆地很可能有一个全球性的应用，所以我们的工作将提供一个框架内，了解污染的原因（S）在世界各地的大多数冲积含水层。对这一机制的理解将有助于决策者在世界各地就开发和避免这类含水层的战略作出选择。这些资料对所有参与水质监测和健康调查的人都很有价值。我们获得的知识可能会改变未来的方法，作为研究，含水层开发和含水层修复。

项目成果

Isolation of an arsenate-respiring bacterium from a redox front in an arsenic-polluted aquifer in West Bengal, Bengal Basin.

• DOI: 10.1021/es504707x
• 发表时间: 2015-03
• 期刊: Environmental science & technology
• 影响因子: 11.4
• 作者: T. H. Osborne;J. McArthur;P. K. Sikdar;J. Santini