Calderon R L
Epidemiology & Biomarkers Branch, Human Studies Division, National Health & Environmental Effects Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC, USA.
Food Chem Toxicol. 2000;38(1 Suppl):S13-20. doi: 10.1016/s0278-6915(99)00133-7.
A number of chemical contaminants have been identified in drinking water. These contaminants reach drinking water supplies from various sources, including municipal and industrial discharges, urban and rural run-off, natural geological formations, drinking water distribution materials and the drinking water treatment process. Chemical contaminants for which epidemiologic studies have reported associations include the following: aluminium, arsenic, disinfection by-products, fluoride, lead, pesticides and radon. Health effects reported have included various cancers, adverse reproductive outcomes, cardiovascular disease and neurological disease. In evaluating epidemiologic studies for risk assessment, considering whether the study design was qualitative (hypothesis generating) or quantitative (hypothesis testing) is important and whether sufficient epidemiologic data of a quantitative nature exists to determine the dose-response curve. Each of the chemical contaminants mentioned are summarized by study designs (qualitative and quantitative) and whether a dose-response curve based on epidemiologic data has been proposed. Environmental epidemiology studies are driven by environmental exposures of interest. For drinking water contaminants, the design of epidemiologic studies and their interpretation should consider the following exposure issues: the source of the contaminant; other sources of the contaminant; the route of exposure; the frequency, duration and magnitude of exposure; the ability to document an actual internal dose; and the ability to document the dose to the target organ. Health effects of concern have other risk factors that must be measured in the conduct of these studies. In evaluating epidemiologic studies, potential errors and biases that may occur must be considered given the very low magnitude of associations (less than 2.0 for either odds ratio or risk ratio). Given the issues, the next generation of drinking water epidemiologic studies should include a multidisciplinary team beyond traditional epidemiologists and statisticians. Study teams will require toxicologists, chemists, engineers and exposure assessors. Arsenic is briefly discussed as an example of the importance of susceptible populations. Disinfection by-products are discussed as an example of epidemiologic studies of mixtures.
饮用水中已发现多种化学污染物。这些污染物通过各种途径进入饮用水供应系统，包括市政和工业排放、城乡径流、天然地质构造、饮用水输送材料以及饮用水处理过程。流行病学研究报告了与之相关的化学污染物如下：铝、砷、消毒副产物、氟化物、铅、农药和氡。报告的健康影响包括各种癌症、不良生殖结局、心血管疾病和神经疾病。在评估用于风险评估的流行病学研究时，考虑研究设计是定性的（提出假设）还是定量的（检验假设）很重要，以及是否存在足够的定量流行病学数据来确定剂量反应曲线。上述每种化学污染物都按研究设计（定性和定量）以及是否已根据流行病学数据提出剂量反应曲线进行了总结。环境流行病学研究由感兴趣的环境暴露驱动。对于饮用水污染物，流行病学研究的设计及其解释应考虑以下暴露问题：污染物的来源；污染物的其他来源；暴露途径；暴露的频率、持续时间和强度；记录实际体内剂量的能力；以及记录靶器官剂量的能力。所关注的健康影响还有其他必须在这些研究中测量的风险因素。在评估流行病学研究时，鉴于关联程度非常低（优势比或风险比均小于2.0），必须考虑可能出现的潜在误差和偏差。鉴于这些问题，下一代饮用水流行病学研究应包括除传统流行病学家和统计学家之外的多学科团队。研究团队将需要毒理学家、化学家、工程师和暴露评估师。作为易感人群重要性的一个例子，简要讨论了砷。作为混合物流行病学研究的一个例子，讨论了消毒副产物。
