State Key Joint Laboratory of Environmental Simulation & Pollution Control, School of Environment, Beijing Normal University, Beijing, 100875, China; Center for Atmospheric Environmental Studies, Beijing Normal University, Beijing, 100875, China.
State Key Joint Laboratory of Environmental Simulation & Pollution Control, School of Environment, Beijing Normal University, Beijing, 100875, China; Center for Atmospheric Environmental Studies, Beijing Normal University, Beijing, 100875, China.
Environ Res. 2020 May;184:109368. doi: 10.1016/j.envres.2020.109368. Epub 2020 Mar 10.
Large areas of mainland China have been suffering frequently from heavy haze pollution during the past years, which feature high concentrations of fine particulate matter (PM, particulate matters with aerodynamic diameters less than 2.5 μm) and low visibility. Moreover, these areas manifested strong regional complex pollution characteristics, particularly in North China including Beijing and the five surrounding provinces (BSFP). In this study, by using the localized comprehensive emission inventory of BSFP region in 2012 as an input, the Comprehensive Air Quality Model with Extensions-Particulate Matter Source Apportionment Technology (CAMx/PSAT) was used to assess the seasonal variations and source apportionment of PM in the highly polluted BSFP region, with a specific focus on the sectoral and sub-regional contributions to PM in Beijing during winter and summer. Results showed that the PM concentrations of BSFP region was higher in winter than that in summer. And the heavily polluted area in BSFP region shrinked noticeably in summer, compared with winter. As for source apportionment of PM, residential and remaining industrial sectors constituted the top two sources of PM mass concentrations in Beijing. In addition, agricultural source represented a major contributor to ammonium, whereas transportation and power sectors constituted major sources to nitrates. In terms of contributions from sub-regions, the local sources ranked as the dominant contributors to PM in Beijing, while the main external contributions originated from the surrounding areas, such as Hebei and Shandong. Results of daily source apportionment to PM in Beijing showed that sub-regional long-distance transport became stronger when haze pollution was severe, in which contribution from remaining industrial sector would be higher than that of other periods. The results will allow for an improved understanding of the causes and origins of heavy regional PM pollution, and thus will benefit the development of effective joint control policies and identification of key polluting emission categories in North China and ultimately serve as references for other highly polluted megacities in the world.
近年来，中国大部分地区经常遭受严重的雾霾污染，其特征是细颗粒物（PM，空气动力学直径小于 2.5μm 的颗粒物）浓度高，能见度低。此外，这些地区表现出强烈的区域复合污染特征，特别是在中国北方地区，包括北京和周边的五个省份（BSFP）。在这项研究中，我们使用了 2012 年 BSFP 地区本地化的综合排放清单作为输入，利用综合空气质量模型扩展-颗粒物源解析技术（CAMx/PSAT）来评估高污染的 BSFP 地区的 PM 的季节性变化和源解析，特别关注冬季和夏季北京的 PM 各部门和次区域的贡献。结果表明，BSFP 地区的 PM 浓度在冬季高于夏季。与冬季相比，BSFP 地区的重污染面积在夏季明显缩小。就 PM 的源解析而言，居住和剩余工业部门构成了北京 PM 质量浓度的前两个主要来源。此外，农业源是铵的主要贡献者，而交通和电力部门则是硝酸盐的主要来源。就次区域的贡献而言，本地来源是北京 PM 的主要贡献者，而外部的主要贡献源则来自周边地区，如河北和山东。北京的 PM 日源解析结果表明，当雾霾污染严重时，次区域的远程传输会更强，剩余工业部门的贡献会高于其他时期。这些结果将有助于更好地了解重区域性 PM 污染的原因和来源，从而有利于制定有效的联合控制政策，并确定华北地区的关键污染排放类别，最终为世界上其他污染严重的特大城市提供参考。
