Massachusetts Department of Environmental Protection, Office of Research and Standards, Boston, Massachusetts 02108, USA.
Environ Health Perspect. 2010 Jan;118(1):42-8. doi: 10.1289/ehp.0900635.
Perchlorate inhibits the uptake of iodide in the thyroid. Iodide is required to synthesize hormones critical to fetal and neonatal development. Many water supplies and foods are contaminated with perchlorate. Exposure standards are needed but controversial. Here we summarize the basis of the Massachusetts (MA) perchlorate reference dose (RfD) and drinking water standard (DWS), which are considerably lower and more health protective than related values derived by several other agencies. We also review information regarding perchlorate risk assessment and policy.
MA Department of Environmental Protection (DEP) scientists, with input from a science advisory committee, assessed a wide range of perchlorate risk and exposure information. Health outcomes associated with iodine insufficiency were considered, as were data on perchlorate in drinking water disinfectants.
We used a weight-of-the-evidence approach to evaluate perchlorate risks, paying particular attention to sensitive life stages. A health protective RfD (0.07 microg/kg/day) was derived using an uncertainty factor approach with perchlorate-induced iodide uptake inhibition as the point of departure. The MA DWS (2 microg/L) was based on risk management decisions weighing information on perchlorate health risks and its presence in certain disinfectant solutions used to treat drinking water for pathogens.
Current data indicate that perchlorate exposures attributable to drinking water in individuals at sensitive life stages should be minimized and support the MA DEP perchlorate RfD and DWS. Widespread exposure to perchlorate and other thyroid toxicants in drinking water and foods suggests that more comprehensive policies to reduce overall exposures and enhance iodine nutrition are needed.
高氯酸盐会抑制甲状腺对碘的摄取。碘是合成对胎儿和新生儿发育至关重要的激素所必需的。许多水供应和食品都受到高氯酸盐的污染。需要制定暴露标准，但存在争议。在这里，我们总结了马萨诸塞州（MA）高氯酸盐参考剂量（RfD）和饮用水标准（DWS）的基础，这两个标准远低于其他几个机构得出的相关值，更能保护健康。我们还审查了有关高氯酸盐风险评估和政策的信息。
马萨诸塞州环境保护部（DEP）的科学家们，在科学顾问委员会的参与下，评估了广泛的高氯酸盐风险和暴露信息。考虑了与碘不足相关的健康结果，以及饮用水消毒剂中高氯酸盐的数据。
我们使用了证据权重方法来评估高氯酸盐的风险，特别关注敏感的生命阶段。使用高氯酸盐诱导的碘摄取抑制作为起点的不确定因素方法得出了健康保护 RfD（0.07μg/kg/天）。马萨诸塞州的 DWS（2μg/L）是基于风险管理决策，权衡了高氯酸盐健康风险及其在某些用于处理饮用水病原体的消毒剂中的存在信息。
目前的数据表明，应尽量减少个体在敏感生命阶段因饮用水而暴露于高氯酸盐的情况，并支持马萨诸塞州 DEP 的高氯酸盐 RfD 和 DWS。广泛暴露于饮用水和食品中的高氯酸盐和其他甲状腺毒物表明，需要采取更全面的政策来减少整体暴露并增强碘营养。
