National Center of Environmental Assessment, Office of Research and Development, US Environmental Protection Agency, Washington, DC 20460, USA.
Environ Health Perspect. 2011 Jan;119(1):125-30. doi: 10.1289/ehp.1002468. Epub 2010 Oct 4.
Quantifying the benefits of reducing hazardous air pollutants (HAPs, or air toxics) has been limited by gaps in toxicological data, uncertainties in extrapolating results from high-dose animal experiments to estimate human effects at lower doses, limited ambient and personal exposure monitoring data, and insufficient economic research to support valuation of the health impacts often associated with exposure to individual air toxics.
To address some of these issues, the U.S. Environmental Protection Agency held the Workshop on Estimating the Benefits of Reducing Hazardous Air Pollutants (HAPs) in Washington, DC, from 30 April to 1 May 2009.
Experts from multiple disciplines discussed how best to move forward on air toxics benefits assessment, with a focus on developing near-term capability to conduct quantitative benefits assessment. Proposed methodologies involved analysis of data-rich pollutants and application of this analysis to other pollutants, using dose-response modeling of animal data for estimating benefits to humans, determining dose-equivalence relationships for different chemicals with similar health effects, and analysis similar to that used for criteria pollutants. Limitations and uncertainties in economic valuation of benefits assessment for HAPS were discussed as well.
These discussions highlighted the complexities in estimating the benefits of reducing air toxics, and participants agreed that alternative methods for benefits assessment of HAPs are needed. Recommendations included clearly defining the key priorities of the Clean Air Act air toxics program to identify the most effective approaches for HAPs benefits analysis, focusing on susceptible and vulnerable populations, and improving dose-response estimation for quantification of benefits.
由于毒理学数据的差距、将高剂量动物实验结果外推以估计低剂量人体效应的不确定性、有限的环境和个人暴露监测数据以及支持与接触个别空气毒物相关的健康影响进行估值的经济研究不足，量化减少有害空气污染物（HAPs，或空气毒物）的益处受到限制。
为了解决其中的一些问题，美国环境保护署于 2009 年 4 月 30 日至 5 月 1 日在华盛顿特区举办了减少有害空气污染物（HAPs）效益评估研讨会。
来自多个学科的专家讨论了如何在空气毒物效益评估方面取得进展，重点是开发近期进行定量效益评估的能力。提出的方法涉及对数据丰富的污染物进行分析，并将这种分析应用于其他污染物，使用动物数据的剂量-反应建模来估计对人类的益处，确定具有相似健康影响的不同化学物质的剂量等效关系，以及类似于用于标准污染物的分析。还讨论了空气毒物效益评估的经济估值的局限性和不确定性。
这些讨论突出了减少空气毒物益处评估的复杂性，与会者一致认为需要替代方法来评估空气毒物的益处。建议包括明确界定清洁空气法空气毒物计划的关键优先事项，以确定空气毒物效益分析的最有效方法，重点关注易感和脆弱人群，并改善剂量-反应估计以量化益处。
