Department of Atmospheric Science, Colorado State University, Fort Collins, Colorado 80521, United States.
Atmospheric Chemistry Division, National Center for Atmospheric Research, Boulder, Colorado 80301, United States.
Environ Sci Technol. 2020 Oct 6;54(19):11838-11847. doi: 10.1021/acs.est.0c04497. Epub 2020 Sep 14.
Wildfires have a significant adverse impact on air quality in the United States (US). To understand the potential health impacts of wildfire smoke, many epidemiology studies rely on concentrations of fine particulate matter (PM) as a smoke tracer. However, there are many gas-phase hazardous air pollutants (HAPs) identified by the Environmental Protection Agency (EPA) that are also present in wildfire smoke plumes. Using observations from the Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption, and Nitrogen (WE-CAN), a 2018 aircraft-based field campaign that measured HAPs and PM in western US wildfire smoke plumes, we identify the relationships between HAPs and associated health risks, PM, and smoke age. We find the ratios between acute, chronic noncancer, and chronic cancer HAPs health risk and PM in smoke decrease as a function of smoke age by up to 72% from fresh (<1 day of aging) to old (>3 days of aging) smoke. We show that acrolein, formaldehyde, benzene, and hydrogen cyanide are the dominant contributors to gas-phase HAPs risk in smoke plumes. Finally, we use ratios of HAPs to PM along with annual average smoke-specific PM to estimate current and potential future smoke HAPs risks.
野火对美国的空气质量有重大的不利影响。为了了解野火烟雾的潜在健康影响，许多流行病学研究依赖细颗粒物 (PM) 浓度作为烟雾示踪剂。然而，环境保护局 (EPA) 还确定了许多存在于野火烟雾羽流中的气相危险空气污染物 (HAPs)。利用美国西部野火云化学、气溶胶吸收和氮（WE-CAN）实验的观测结果，这是 2018 年的一次基于飞机的野外活动，测量了美国西部野火烟雾羽流中的 HAPs 和 PM，我们确定了 HAPs 与相关健康风险、PM 和烟雾年龄之间的关系。我们发现，随着烟雾年龄的增加（从新鲜的<1 天老化到旧的>3 天老化），急性、慢性非癌症和慢性癌症 HAPs 健康风险与 PM 之间的比值下降了高达 72%。我们表明，丙烯醛、甲醛、苯和氰化氢是烟雾羽流中气相 HAPs 风险的主要贡献者。最后，我们使用 HAPs 与 PM 的比值以及每年平均烟雾特异性 PM 来估计当前和潜在的未来烟雾 HAPs 风险。
