University of Texas at Austin, Texas, USA.
Environ Sci Technol. 2011 Nov 15;45(22):9484-97. doi: 10.1021/es2022818. Epub 2011 Oct 21.
Policy Relevant Background (PRB) ozone concentrations are defined by the United States (U.S.) Environmental Protection Agency (EPA) as those concentrations that would occur in the U.S. in the absence of anthropogenic emissions in continental North America (i.e., the U.S, Canada, and Mexico). Estimates of PRB ozone have had an important role historically in the EPA's human health and welfare risk analyses used in establishing National Ambient Air Quality Standards (NAAQS). The margin of safety for the protection of public health in the ozone rulemaking process has been established from human health risks calculated based on PRB ozone estimates. Sensitivity analyses conducted by the EPA have illustrated that changing estimates of PRB ozone concentrations have a progressively greater impact on estimates of mortality risk as more stringent standards are considered. As defined by the EPA, PRB ozone is a model construct, but it is informed by measurements at relatively remote monitoring sites (RRMS). This review examines the current understanding of PRB ozone, based on both model predictions and measurements at RRMS, and provides recommendations for improving the definition and determination of PRB ozone.
政策相关背景（PRB）臭氧浓度由美国环境保护署（EPA）定义为在北美大陆（即美国、加拿大和墨西哥）没有人为排放的情况下，美国可能出现的浓度。在 EPA 用于制定国家环境空气质量标准（NAAQS）的人类健康和福利风险分析中，PRB 臭氧的估计值在历史上一直发挥着重要作用。在臭氧法规制定过程中，保护公众健康的安全裕度是根据基于 PRB 臭氧估计值计算的人类健康风险来确定的。EPA 进行的敏感性分析表明，随着更严格标准的考虑，PRB 臭氧浓度估计值的变化对死亡率风险估计值的影响越来越大。根据 EPA 的定义，PRB 臭氧是一个模型结构，但它是通过相对偏远监测站点（RRMS）的测量来提供信息的。本综述基于 RRMS 的模型预测和测量，考察了 PRB 臭氧的当前认识，并为改进 PRB 臭氧的定义和确定提供了建议。
