Increases in wintertime PM2.5 sodium and chloride linked to snowfall and road salt application
Increases in wintertime PM2.5 sodium and chloride linked to snowfall and road salt application
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冬季 PM2.5 钠和氯化物的增加与降雪和道路盐的施用有关
DOI：
10.1016/j.atmosenv.2018.01.008
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发表时间：
2018
影响因子：
5
通讯作者：
K. Pratt
中科院分区：
文献类型：
--
作者：
K. R. Kolesar;Claire N. Mattson;P. Peterson;N. May;Rashad K. Prendergast;K. Pratt
在许多城市的冬季，在道路上使用盐类和咸水是一种常见的做法。道路盐可以被雾化，从而向大气中注入钠和氯颗粒物(PM)。在这里，来自美国环境保护局化学形态监测网的数据被用来评估美国25个地点的钠和氯PM2.5(PM <； 2.5 μm)的时间趋势，以调查道路盐气溶胶的无处不在。对于年平均降雪量大于25 cm的地区，冬季的钠和氯PM2.5浓度平均比夏季高出三倍。可归因于道路盐的冬季城市氯化物PM2.5浓度有时甚至可以与沿海受海雾气溶胶影响的地点的浓度相媲美。在大多数受降雪影响的城市，氯化物和钠PM2.5浓度与降雪量呈正相关；然而，这种关系因各州和地方冬季维护做法的差异而变得复杂。这项研究强调了美国道路盐气溶胶的普遍存在及其对冬季城市空气质量的潜在影响，特别是由于多相反应可能从颗粒物相中释放氯。由于道路盐应用是世界各地冬季城市环境中的一种常见做法，因此必须通过测量和建模来调查目前未列入清单的道路盐应用排放量及其影响。
The application of salts and salty brines to roads is common practice during the winter in many urban environments. Road salts can become aerosolized, thereby injecting sodium and chloride particulate matter (PM) into the atmosphere. Here, data from the United States Environmental Protection Agency Chemical Speciation Monitoring Network were used to assess temporal trends of sodium and chloride PM2.5(PM < 2.5 μm) at 25 locations across the United States to investigate the ubiquity of road salt aerosols. Sodium and chloride PM2.5concentrations were an average of three times higher in the winter, as compared to the summer, for locations with greater than 25 cm of average annual snowfall. Winter urban chloride PM2.5concentrations attributed to road salt can even sometimes rival those of coastal sea spray aerosol-influenced sites. In most snow-influenced cities, chloride and sodium PM2.5concentrations were positively correlated with snowfall; however, this relationship is complicated by differences in state and local winter maintenance practices. This study highlights the ubiquity of road salt aerosols in the United States and their potential impact on wintertime urban air quality, particularly due to the potential for multiphase reactions to liberate chlorine from the particle-phase. Since road salt application is a common practice in wintertime urban environments across the world, it is imperative that road salt application emissions, currently not included in inventories, and its impacts be investigated through measurements and modeling.