Singh Subraham, Johnson Glen, Kavouras Ilias G
Department of Environmental, Occupational, and Geospatial Health Sciences, City University of New York Graduate School of Public Health and Health Policy, New York, NY, USA.
Environ Health Insights. 2022 Jun 7;16:11786302221104016. doi: 10.1177/11786302221104016. eCollection 2022.
Declining ambient PM concentrations have been attributed to fuel consumption standards and emission controls of secondary sulfate and nitrate aerosol precursors from transportation and industrial sectors. As a result, the relative contribution of PM sources is modified, shifting PM trends, physicochemical characteristics, and health effects. Carbonaceous fine aerosol account for most of PM mass in the US. This study aims to examine the spatiotemporal trends of ambient PM levels and their association with primary PM emissions from anthropogenic activities and fires in the New York/New Jersey metropolitan statistical area (NYNJ MSA) airshed. PM mass concentrations were obtained from the U.S. Environmental Protection Agency (USEPA) Air Data. Ambient PM mass levels declined on average by 47%, at a rate of -0.61 ± 0.01 μg/m/year in urban locations and -0.25 ± 0.01 μg/m/year in upwind and peri-urban locations over the 2007 to 2017 period. The strong spatial gradient in 2007, with high PM levels in urban locations and low PM levels in peri-urban locations gradually weakened by 2013 but re-appeared in 2017. Over the same period, primary PM emissions declined by 52% from transportation, 15% from industrial, and 8% from other anthropogenic sources corresponding to a decrease of 0.8, 0.9, and 0.6 μg/m on ambient PM mass, respectively. Wildland and prescribed fires emissions increased more than 3 times adding 0.8 μg/m to ambient PM mass. These results indicate that (i) fire emissions may impede the effectiveness of existing policies to improve air quality and (ii) the chemical content of PM may be changing to an evolving mixture of aromatic and oxygenated organic species with differential toxicological responses as compared to inert ammonium sulfate and nitrate salts.
环境细颗粒物（PM）浓度的下降归因于燃料消耗标准以及对交通运输和工业部门二次硫酸盐和硝酸盐气溶胶前体的排放控制。因此，PM源的相对贡献发生了变化，从而改变了PM的趋势、理化特性和健康影响。在美国，碳质细颗粒物占PM质量的大部分。本研究旨在考察纽约/新泽西大都市统计区（NYNJ MSA）空域环境PM水平的时空趋势及其与人为活动和火灾产生的一次PM排放之间的关联。PM质量浓度数据来自美国环境保护局（USEPA）的空气质量数据。在2007年至2017年期间，城市地区环境PM质量水平平均下降了47%，下降速率为-0.61±0.01μg/m³/年，上风和城郊地区为-0.25±0.01μg/m³/年。2007年存在很强的空间梯度，城市地区PM水平高，城郊地区PM水平低，到2013年这种梯度逐渐减弱，但在2017年又重新出现。同一时期，交通运输源的一次PM排放下降了52%，工业源下降了15%，其他人为源下降了8%，相应地环境PM质量分别下降了0.8、0.9和0.6μg/m³。荒地和规定燃烧产生的排放增加了3倍多，使环境PM质量增加了0.8μg/m³。这些结果表明：（i）火灾排放可能会阻碍现有改善空气质量政策的有效性；（ii）与惰性硫酸铵和硝酸盐相比，PM的化学组成可能正在转变为一种由芳香族和含氧有机物种组成的不断变化的混合物，且具有不同的毒理学反应。
