Cardno ChemRisk, San Francisco, CA 94104, United States of America.
Cardno ChemRisk, Aliso Viejo, CA 92656, United States of America.
Sci Total Environ. 2021 Mar 20;761:144107. doi: 10.1016/j.scitotenv.2020.144107. Epub 2020 Dec 13.
Perfluorooctanoic acid (PFOA) is a synthetic, perfluorinated organic acid previously used in fluoropolymer production in the United States. PFOA has been a recent focal point for regulation because of its ubiquitous presence in drinking water throughout the United States. In 2016, the United States Environmental Protection Agency (US EPA) issued a lifetime drinking water Health Advisory (HA) for PFOA of 0.07 μg/L; several states have also implemented their own drinking water guidelines for PFOA. The current study aimed to evaluate the basis and derivation of state and federal guidelines for PFOA in drinking water, with particular emphasis on the exposure parameters utilized. Twelve distinct PFOA drinking water standards were identified ranging from 0.0051 to 2 μg/L. The US EPA HA assumptions were evaluated using a Monte Carlo analysis that included distributions for drinking water intake (DWI) rate and the relative source contribution (RSC). We determined that US EPA's HA of 0.07 μg/L is protective of 99% of the population of lactating women. We also demonstrated that the health-based guidelines were highly variable across states and that the actual RSC of PFOA from drinking water is likely greater than 20%, based on studies of actual PFOA exposures from dust, water, and food. A sensitivity analysis was performed using the same equations as the US EPA, while substituting the RSC and DWI variables; resulting in HAs ranging from 0.074 to 0.346 μg/L. We also evaluated the contribution of PFOA in drinking water to the systemic PFOA body burden of the general population using an available biokinetic model. We conclude that more rigorous efforts are warranted to establish consistent health-based drinking water guidelines for PFOA, given that drinking water is a primary source of human exposure to PFOA in the United States.
全氟辛酸（PFOA）是一种合成的全氟有机酸，曾在美国氟聚合物生产中使用。由于其在美国各地饮用水中的普遍存在，PFOA 成为最近监管的焦点。2016 年，美国环境保护署（US EPA）发布了 PFOA 的终身饮用水健康咨询（HA）值为 0.07μg/L；几个州也已经为 PFOA 实施了自己的饮用水指南。本研究旨在评估美国和联邦饮用水中 PFOA 指南的依据和推导，特别强调所使用的暴露参数。确定了 12 个不同的 PFOA 饮用水标准，范围从 0.0051 到 2μg/L。使用包含饮用水摄入量（DWI）率和相对源贡献（RSC）分布的蒙特卡罗分析评估了 US EPA 的 HA 假设。我们确定，US EPA 的 0.07μg/L 的 HA 可保护 99%的哺乳期妇女人群。我们还表明，各州的基于健康的指南差异很大，并且根据实际的 PFOA 从灰尘、水和食物中的暴露研究，饮用水中的实际 PFOA RSC 可能大于 20%。使用与 US EPA 相同的方程进行了敏感性分析，同时替代了 RSC 和 DWI 变量；结果导致 HA 值范围从 0.074 到 0.346μg/L。我们还使用可用的生物动力学模型评估了饮用水中 PFOA 对一般人群系统 PFOA 体负荷的贡献。我们得出结论，鉴于饮用水是美国 PFOA 暴露的主要来源，因此需要做出更严格的努力来制定一致的基于健康的 PFOA 饮用水指南。
