School of Geography, Nantong University, Nantong, China.
Jiangsu Yangtze River Economic Belt Research Institute, Nantong, China.
Integr Environ Assess Manag. 2021 Sep;17(5):1014-1024. doi: 10.1002/ieam.4399. Epub 2021 Mar 15.
Particulate matter in the air seriously affects human health and has been a hot topic of discussion. Because of the coronavirus disease 2019 (COVID-19) lockdown in cities in China, sources of particulate matter, including gasoline-burning vehicles, dust-producing building sites, and coal-fired factories, almost all ceased at the end of January 2020. It was not until early April that outdoor activities recovered. Ten cities were selected as observation sites during the period from 19 December 2019 to 30 April 2020, covering the periods of preclosure, closure, and gradual resumption. A total of 11 720 groups of data were obtained, and 4 indicators were used to assess the characteristics of the particle pollution in the period. The quality of the atmospheric environment was visibly influenced by human activities in those 5 mo. The concentrations of particulate matter with particle sizes below 10 µm (PM10) decreased slightly in February and March and then began to increase slowly after April with the gradual recovery of production. The concentrations of particulate matter with particle sizes below 2.5 µm (PM2.5) decreased greatly in most regions, especially in northern cities, during closure and maintained a relatively stable level in the following 3 mo. The trends of PM10 and PM2.5 indicated that the reduced human activities during the COVID-19 lockdown decreased the concentrations of particulate matter in the air, and the difference between the PM10 and PM2.5 trends might be due to the different sources of the 2 particles and their different aerodynamics. However, during closure, the particulate matter pollution in the cities remained at a high level, which indicated that some ignored factors other than outdoor production activities, automobile exhaust, and construction site dust might have contributed greatly to the PM10 and PM2.5 concentrations, and the tracing of the particulate matter should be given further attention in environmental management. Integr Environ Assess Manag 2021;17:1014-1024. © 2021 SETAC.
空气中的颗粒物严重影响人类健康，一直是讨论的热点。由于中国城市 2019 年冠状病毒病（COVID-19）封锁，颗粒物的来源，包括燃烧汽油的车辆、产生灰尘的建筑工地和燃煤工厂，几乎在 2020 年 1 月底全部停止。直到 4 月初，户外活动才恢复。在 2019 年 12 月 19 日至 2020 年 4 月 30 日期间，选择了 10 个城市作为观测点，涵盖了关闭前、关闭中和逐步恢复的时期。共获得了 11720 组数据，并使用 4 个指标来评估该时期颗粒污染的特征。在这 5 个月里，人类活动明显影响了大气环境质量。在生产逐步恢复后，PM10 和 PM2.5 的浓度在 2 月和 3 月略有下降，然后从 4 月开始缓慢上升。在大多数地区，尤其是北方城市，PM2.5 的浓度在关闭期间大幅下降，在随后的 3 个月中保持相对稳定的水平。PM10 和 PM2.5 的趋势表明，COVID-19 封锁期间人类活动的减少降低了空气中颗粒物的浓度，PM10 和 PM2.5 趋势的差异可能是由于这两种颗粒的不同来源及其不同的空气动力学特性。然而，在关闭期间，城市的颗粒物污染仍处于较高水平，这表明除了户外生产活动、汽车尾气和建筑工地扬尘等因素外，一些被忽视的因素可能对 PM10 和 PM2.5 浓度有很大贡献，在环境管理中应进一步关注颗粒物的溯源。综合环境评估与管理 2021；17:1014-1024。©2021 SETAC。
