Air toxics and health risks in California: The public health implications of outdoor concentrations
Air toxics and health risks in California: The public health implications of outdoor concentrations
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DOI：
10.1111/0272-4332.202026
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发表时间：
2000-04-01
期刊：
影响因子：
3.8
通讯作者：
Caldwell, JC
中科院分区：
文献类型：
--
作者：
Morello-Frosch, RA;Woodruff, TJ;Caldwell, JC
在《清洁空气法》列出的188种有害空气污染物中，只有少数几种有关于人类健康影响的信息，主要来自动物和职业研究。由于缺乏关于环境空气有毒物质的一致监测数据，因此难以评估可能影响人类健康的低水平、慢性、环境接触有害生物和农药的程度，并限制了优先考虑和评估减排政策举措的努力。模拟室外HAP浓度估计从美国环境保护署的累积暴露项目被用来表征的程度，空气有毒物质的问题在加州的基准年1990年。这些空气有毒物质浓度估计值与慢性毒性数据一起用于估计单个HAP的癌症和非癌症危害以及多种污染物造成的风险。虽然有害的空气污染物在环境中无处不在，但环境暴露造成的潜在癌症和非癌症健康危害在地理上集中在三个城市化地区和几个农村县。这项分析估计，所有空气有毒物质浓度的平均超额个体癌症风险为2.7E（-4），8600例超额终身癌症病例，其中70%可归因于四种污染物：多环有机物，1，3丁二烯，甲醛和苯。对于非癌症效应，分析估计了代表所有HAP综合效应的总危险指数。每种污染物都以估计浓度与参考浓度之比作为指数。人口普查区的指数中位数为17，主要是由于丙烯醛和铬浓度估计。平均而言，HAP浓度以及癌症和非癌症健康风险主要来自区域和移动的源排放，尽管该州有几个地点的点源占估计浓度和健康风险的很大一部分。本研究的风险估计可以为优先考虑研究，监测和监管干预活动提供指导，以减少对普通人群的潜在危害。改进环境监测工作有助于澄清这一分析中固有的不确定性。
Of the 188 hazardous air pollutants (HAPs) listed in the Clean Air Act, only a handful have information on human health effects, derived primarily from animal and occupational studies. Lack of consistent monitoring data on ambient air toxics makes it difficult to assess the extent of low-level, chronic, ambient exposures to HAPs that could affect human health, and limits attempts to prioritize and evaluate policy initiatives for emissions reduction. Modeled outdoor HAP concentration estimates from the U.S. Environmental Protection Agency's Cumulative Exposure Project were used to characterize the extent of the air toxics problem in California for the base year of 1990. These air toxics concentration estimates were used with chronic toxicity data to estimate cancer and noncancer hazards for individual HAPs and the risks posed by multiple pollutants. Although hazardous air pollutants are ubiquitous in the environment, potential cancer and noncancer health hazards posed by ambient exposures are geographically concentrated in three urbanized areas and in a few rural counties. This analysis estimated a median excess individual cancer risk of 2.7E(-4) for all air toxics concentrations and 8600 excess lifetime cancer cases, 70% of which were attributable to four pollutants: polycyclic organic matter, 1,3 butadiene, formaldehyde, and benzene. For noncancer effects, the analysis estimated a total hazard index representing the combined effect of all HAPs considered. Each pollutant contributes to the index a ratio of estimated concentration to reference concentration. The median value of the index across census tracts was 17, due primarily to acrolein and chromium concentration estimates. On average, HAP concentrations and cancer and noncancer health risks originate mostly from area and mobile source emissions, although there are several locations in the state where point sources account for a large portion of estimated concentrations and health risks. Risk estimates from this study can provide guidance for prioritizing research, monitoring, and regulatory intervention activities to reduce potential hazards to the general population. Improved ambient monitoring efforts can help clarify uncertainties inherent in this analysis.