Biocomplexity IDEA: Portable Devices To Map The Distribution of Arsenic In Bangladesh Groundwater & The Relation To Sediment Structure

孟加拉国地下水中的Van Geenarcic浓度在几十米的横向和垂直空间尺度内可以变化三个数量级。这种极端的变异性是一系列鲜为人知的水文、微生物和地球化学相互作用的结果，这些相互作用反映了恒河-雅鲁藏布江三角洲过去10,000年来的复杂演化。在较短的时间尺度上，这些复杂的格局也可能有时间维度，潜在地，地下水砷对季风和灌溉地下水使用量的增加有反应。了解这些模式具有直接的社会意义，因为目前至少有2,500万人因饮用含有50微克/L砷的管井中的地下水而中毒，这些管井符合孟加拉国和(直到最近)美国的饮用水标准。他建议在“环境活动仪器开发(IDEA)”专题领域下进行勘探工作，其核心是这样一个概念，即只有通过收集代表从米到公里的现场条件的地球物理、地球化学以及最终的微生物学数据，才能了解孟加拉国地下水中砷的分布原理。考虑到这一目标，并作为对其目前在孟加拉国开展的由NIEHS/Superfund基础研究计划资助的工作的补充，这个跨学科的科学家团队努力开发和测试两种便携式设备，它们利用现有管井的无辐射Ar射线来测量地下水的关键特性：(1)用高精度的双束量热仪测量地下水中的砷浓度；(2)用电磁导率仪测量垂直沉积物结构。同时，我们将开始开发必要的统计工具，以解释和整合可用这些工具生成的复杂数据集。我们的意图是为一项全面的生物复杂性提案奠定基础，该提案旨在提高我们对一系列复杂的相互作用的基本理解，包括微生物和社会因素，这些因素导致了一场令人震惊的人类悲剧。

0119933Van GeenArsenic concentrations in groundwater of Bangladesh can vary by three orders magnitude within lateral and vertical spatial scales of tens of meters. This extreme variability is the result of a poorly understood set of hydrological, microbial, and geochemical interactions that reflect the complex evolution of the Ganges-Brahmaputra delta over the past 10,000 years. There may also be a temporal dimension to these complex pattems on shorter time scales with, potentially, a response of groundwater arsenic to the monsoon and to increased groundwater usage for irrigation. Understanding these pattems has immediate societal relevance because at least 25 million people are currently poisoned by drinking groundwater from millions of tube wells containing 50 ug/L arsenic, the Bangladesh and (until very recently) US drinking water standard.T'his proposal for exploratory work under the topical area "Instrumentation Development for Environmental Activities (IDEA)" is centered around the notion that the principles underlying the distribution of arsenic in Bangladesh groundwater can be understood only through the collection of geophysical, geochemical, and eventually microbiological, data representative of in situ conditions on spatial scales ranging from meters to kilometers. With this objective in mind, and as a complement to its current work in Bangladesh supported by the NIEHS/Superfund Basic Research Program, this interdisciplinary team of scientists seeks to develop and test two portable devices that measure key properties of the subsurface by taking advantage of the enonnous ar-ray of existing tube wells: (1) groundwater arsenic concentrations with a high-precision, double-beam calorimeter, (2) the vertical sediment structure by electromagnetic conductivity. In parallel, we will start to develop the statistical tools needed to interpret and integrate the complex data sets that can be generated with these instruments. Our intention is to set the stage for a full-scale Biocomplexity proposal aimed at improving our ftindamental understanding of the complex set of interactions, including microbial and societal factors, that resulted in a human tragedy of staggering dimension.0119933