Tang Min, Lytle Darren, Achtemeier Riley, Tully Jennifer
Oak Ridge Institute for Science and Education (ORISE) Fellow at U.S. Environmental Protect Agency, Office of Research and Development, Center for Environmental Solutions & Emergency Response, Water Infrastructure Division, 26 W. Martin Luther King Dr., Cincinnati, OH 45268, United States; CDM Smith, 11500 Northlake Dr # 305, Cincinnati, OH 45249, United States.
U.S. Environmental Protect Agency, Office of Research and Development, Center for Environmental Solutions & Emergency Response, Water Infrastructure Division, 26 W. Martin Luther King Dr., Cincinnati, OH 45268, United States.
Water Res. 2023 Oct 1;244:120425. doi: 10.1016/j.watres.2023.120425. Epub 2023 Jul 28.
Properly certified NSF/ANSI 53 water filters are distributed as a temporary measure to protect residents from risk of exposure to elevated lead (Pb) levels resulting from water system changes and various activities. Water consumers and other stakeholders have raised questions on the performance of these filters in field settings, particularly in cases where water Pb levels exceeded the NSF/ANSI 53 challenge water level of 150 µg/L and when Pb phosphate nanoparticles (≤ 200 nm) were present in drinking water. This literature review summarizes findings from 23 studies that evaluated the ability of NSF/ANSI 53 post-2007 certified filters to reduce soluble and/or particulate Pb from water. The studies in total examined 1,486 faucet-mounted, 25 under-the-sink, and 167 pitcher filters, with 1,528 filters used in field studies and 150 filters in laboratory studies. This review found that filter performance varied with different filter type, test water source, and initial unfiltered total Pb concentration. 99% (1,512/1,528) of the filters used in field studies removed Pb to at or below the certification benchmark of pre-2019, 10 µg/L or post-2019, 5 µg/L. In contrast, 61% (91/150) of the filters used in laboratory studies reduced Pb to the benchmark. Laboratory filters were often tested under conditions beyond what they were certified to handle. Pb concentration, particle form and size, improper operation and maintenance of certified water filters were attributed to reported filter failures. This information is intended to help water utilities, regulators, and others make decisions regarding the deployment of water filters to the public when drinking water Pb exposure concerns have been raised.
经过适当认证的NSF/ANSI 53水过滤器作为一项临时措施进行分发，以保护居民免受因水系统变化和各种活动导致的铅（Pb）含量升高的风险。用水户和其他利益相关者对这些过滤器在实际使用环境中的性能提出了疑问，特别是在水中铅含量超过NSF/ANSI 53规定的150微克/升挑战水位以及饮用水中存在磷酸铅纳米颗粒（≤200纳米）的情况下。这篇文献综述总结了23项研究的结果，这些研究评估了2007年后通过NSF/ANSI 53认证的过滤器从水中去除可溶性和/或颗粒态铅的能力。这些研究总共检测了1486个水龙头安装式过滤器、25个台下式过滤器和167个 pitcher过滤器，其中1528个过滤器用于实地研究，150个过滤器用于实验室研究。该综述发现，过滤器的性能因过滤器类型、测试水源和初始未过滤总铅浓度的不同而有所差异。实地研究中使用的过滤器有99%（1512/1528）将铅去除至2019年前的认证基准10微克/升或2019年后的5微克/升及以下。相比之下，实验室研究中使用的过滤器有61%（91/150）将铅降低至基准水平。实验室过滤器经常在超出其认证处理能力的条件下进行测试。铅浓度、颗粒形态和大小、认证水过滤器操作和维护不当被认为是导致过滤器故障的原因。这些信息旨在帮助自来水公司、监管机构和其他各方在出现饮用水铅暴露问题时，就向公众部署水过滤器做出决策。
