美国环境保护局（USEPA）于1991年7月18日提出了针对六种放射性核素（包括氡）的国家饮用水法规。针对这项拟议规则提交的600多套评论中的一套，大部分集中在氡上。对于如何控制饮用水中的氡，评论意见分歧很大。关于氡最大污染水平（MCL）的最合适水平，意见分歧很大。本文的重点是概述已提交的有关radon MCL的评论以及当前辩论背后的问题。包括12篇参考文献。

The U.S. Environmental Protection Agency (USEPA) proposed National Drinking Water Regulations July 18, 1991, for six radionuclides, including radon. One of the more than 600 sets of comments submitted in response to this proposed rule, most focused on radon. Comments are sharply divided over how radon should be regulated in drinking water. Opinions about the most appropriate level for the radon maximum contaminant level (MCL) are widely divergent. An overview of submitted comments regarding the radon MCL and the issues behind the current debate are the focus of this article. Includes 12 references.