Case study approach to modeling historical disinfection by-product exposure in Iowa drinking waters
Case study approach to modeling historical disinfection by-product exposure in Iowa drinking waters
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DOI：
10.1016/j.jes.2017.03.007
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发表时间：
2017-08-01
影响因子：
6.9
通讯作者：
Amy, Gary
中科院分区：
文献类型：
--
作者：
Krasner, Stuart W.;Cantor, Kenneth P.;Amy, Gary
20世纪80年代，美国爱荷华州开展了一项病例对照流行病学研究，分析消毒副产物（DBPs）暴露与膀胱癌风险之间的关系。三卤甲烷（THMs）是饮用水中最常见和最主要的DBP类别，可作为全DBP混合物的主要度量和替代品。平均THM暴露量是根据爱荷华州过去水平的粗略估计计算出来的。为了减少错误分类，进行了一项后续研究，以改善对过去THM水平的估计，并重新评估其与癌症风险的关系。此外，还研究了与另一类dbp——卤乙酸相关的风险。在最初的分析中，根据氯化点的不同，地表水处理厂被指定为两种可能的THM水平之一。重新评估考虑了每个处理地表水或地下水的公用事业单位的具体情况。结合实际DBP测量考虑了多种处理/消毒方案和水质参数，以估算过去的DBP水平。重新分析的THM年平均水平最高为156 μ g/L，而原始分析为74 μ g/L。这样就可以对暴露在较高水平（bb0 - 96 μ g/L）的受试者进行分析。基于案例研究和对影响DBP形成的水质和操作参数的理解，重新分析建立了一种新的方法，用于确定历史暴露量。(C) 2017中国科学院生态环境科学研究中心Elsevier B.V.出版
In the 1980s, a case-control epidemiologic study was conducted in Iowa (USA) to analyze the association between exposure to disinfection by-products (DBPs) and bladder cancer risk. Trihalomethanes (THMs), the most commonly measured and dominant class of DBPs in drinking water, served as a primary metric and surrogate for the full DBP mixture. Average THM exposure was calculated, based on rough estimates of past levels in Iowa. To reduce misclassification, a follow-up study was undertaken to improve estimates of past THM levels and to re-evaluate their association with cancer risk. In addition, the risk associated with haloacetic acids, another class of DBPs, was examined. In the original analysis, surface water treatment plants were assigned one of two possible THM levels depending on the point of chlorination. The re-assessment considered each utility treating surface or groundwater on a case-by-case basis. Multiple treatment/disinfection scenarios and water quality parameters were considered with actual DBP measurements to develop estimates of past levels. The highest annual average THM level in the re-analysis was 156 mu g/L compared to 74 mu g/L for the original analysis. This allowed the analysis of subjects exposed at higher levels (>96 mu g/L). The re-analysis established a new approach, based on case studies and an understanding of the water quality and operational parameters that impact DBP formation, for determining historical exposure. (C) 2017 The Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V.