| Title: | "Driving Forces of Changes in Air Quality during the COVID-19 Lockdown Period in the Yangtze River Delta Region, China" |
| Author(s): | Liu T; Wang X; Hu J; Wang Q; An J; Gong K; Sun J; Li L; Qin M; Li J; Tian J; Huang Y; Liao H; Zhou M; Hu Q; Yan R; Wang H; Huang C; |
| Address: | "Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Nanjing University of Information Science & Technology, Nanjing 210044, China. State Environmental Protection Key Laboratory of Formation and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai 200233, China" |
| DOI: | 10.1021/acs.estlett.0c00511 |
| Abstract: | "During the COVID-19 lockdown period (from January 23 to February 29, 2020), ambient PM(2.5) concentrations in the Yangtze River Delta (YRD) region were observed to be much lower, while the maximum daily 8 h average (MDA8) O(3) concentrations became much higher compared to those before the lockdown (from January 1 to 22, 2020). Here, we show that emission reduction is the major driving force for the PM(2.5) change, contributing to a PM(2.5) decrease by 37% to 55% in the four YRD major cities (i.e., Shanghai, Hangzhou, Nanjing, and Hefei), but the MDA8 O(3) increase is driven by both emission reduction (29%-52%) and variation in meteorological conditions (17%- 49%). Among all pollutants, reduction in emissions mainly of primary PM contributes to a PM(2.5) decrease by 28% to 46%, and NOx emission reduction contributes 7% to 10%. Although NOx emission reduction dominates the MDA8 O(3) increase (38%-59%), volatile organic compounds (VOCs) emission reduction lead to a 5% to 9% MDA8 O(3) decrease. Increased O(3) promotes secondary aerosol formation and partially offsets the decrease of PM(2.5) caused by the primary PM emission reductions. The results demonstrate that more coordinated air pollution control strategies are needed in YRD" |
| Notes: | "PubMed-not-MEDLINELiu, Ting Wang, Xueying Hu, Jianlin Wang, Qian An, Jingyu Gong, Kangjia Sun, Jinjin Li, Lin Qin, Momei Li, Jingyi Tian, Junjie Huang, Yiwei Liao, Hong Zhou, Min Hu, Qingyao Yan, Rusha Wang, Hongli Huang, Cheng eng 2020/09/14 Environ Sci Technol Lett. 2020 Sep 14; 7(11):779-786. doi: 10.1021/acs.estlett.0c00511. eCollection 2020 Nov 10" |
