College of Geography and Environment, Shandong Normal University, Jinan, 250014, China.
Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Fudan Tyndall Centre, Department of Environmental Science & Engineering, Fudan University, Shanghai, 200433, China.
Environ Sci Pollut Res Int. 2020 Aug;27(22):27750-27761. doi: 10.1007/s11356-020-09070-y. Epub 2020 May 12.
Frequent heavy air pollution occurred during the winter heating season of northern China. In this study, PM (particles with an aerodynamic diameter less than 2.5 μm) was collected from a coastal city of China during the winter heating season from January 1 to March 31, 2018, and the soluble ions, organic carbon (OC), elemental carbon (EC), bacterial, endotoxin, and fungal concentration in PM were analyzed. During the winter heating season, PM and bioaerosols increased on polluted days, and the secondary inorganic ions, including NO, NH, and SO, increased significantly. Meteorological factors, such as wind direction and wind speed, had major impacts on the distributions of PM and bioaerosols. Pollutant concentration was high when there was a westerly wind with the speed of 3-6 m/s from inland area. Using the air mass backward trajectories and principal component analysis, we elucidate the potential origins of bioaerosol in PM. The backward trajectory suggested that air mass for polluted samples (PM > 75 μg/m) commonly originated from continent (9.62%), whereas air masses for clean samples (PM < 35 μg/m) were mainly from marine (56.73%). The interregional transport of pollutants from continental area contributed most to PM. Principal component analysis of the water-soluble ions and bioaerosol indicated that air pollution of the coastal city was greatly affected by coal combustion, biomass burning, and regional transmission of high-intensity pollutants from continent. Among that, interregional transport, biomass burning, and dust from soil and plants were main sources of bioaerosol. Our findings provide important insights into the origins and characteristics of bioaerosol in PM during the winter heating season of the coastal city in northern China.
在中国北方的冬季供暖季节，频繁发生重度空气污染。本研究于 2018 年 1 月 1 日至 3 月 31 日在一个沿海城市采集了供暖季的 PM（空气动力学直径小于 2.5μm 的颗粒物），并分析了 PM 中的可溶性离子、有机碳（OC）、元素碳（EC）、细菌、内毒素和真菌浓度。在冬季供暖季节，污染日 PM 和生物气溶胶增加，二次无机离子（包括 NO、NH 和 SO）显著增加。风向和风速等气象因素对 PM 和生物气溶胶的分布有重大影响。当内陆地区风速为 3-6m/s 的西风时，污染物浓度较高。利用气团后向轨迹和主成分分析，阐明了 PM 中生物气溶胶的潜在来源。后向轨迹表明，污染样品（PM>75μg/m）的气团通常来源于大陆（9.62%），而清洁样品（PM<35μg/m）的气团主要来源于海洋（56.73%）。来自大陆地区的污染物的区域间输送对 PM 的贡献最大。对水溶性离子和生物气溶胶的主成分分析表明，沿海城市的空气污染受煤燃烧、生物质燃烧以及大陆高强度污染物的区域传输的影响较大。其中，区域间传输、生物质燃烧和土壤及植物的尘埃是生物气溶胶的主要来源。本研究结果为了解冬季供暖季节中国北方沿海城市 PM 中生物气溶胶的来源和特征提供了重要信息。
