|
1
|
Bai Y, Wang Z, Xie F, Cen L, Xie Z, Zhou X, He J, Lü C. Changes in stoichiometric characteristics of ambient air pollutants pre-to post-COVID-19 in China. Environ Res 2022; 209:112806. [PMID: 35101403 PMCID: PMC8800168 DOI: 10.1016/j.envres.2022.112806] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 01/10/2022] [Accepted: 01/21/2022] [Indexed: 05/06/2023]
Abstract
To prevent the Corona Virus Disease 2019 (COVID-19) spreading, Chinese government takes a series of corresponding measures to restrict human mobility, including transportation lock-down and industries suspension, which significantly influenced the ambient air quality and provided vary rare time windows to assess the impacts of anthropological activities on air pollution. In this work, we divided the studied timeframe (2019/12/24-2020/2/24) into four periods and selected 88 cities from 31 representative urban agglomerations. The indicators of PM2.5/PM10 and NO2/SO2 were applied, for the first time, to analyze the changes in stoichiometric characteristics of ambient air pollutants pre-to post-COVID-19 in China. The results indicated that the ratios of NO2/SO2 presented a responding decline, especially in YRD (-5.01), YH (-3.87), and MYR (-3.84), with the sharp reduction of traffic in post-COVID-19 periods (P3-P4: 2.34 ± 0.94 m/m) comparing with pre-COVID-19 periods (P1-P2: 4.49 ± 2.03 m/m). Whereas the ratios of PM2.5/PM10 increased in P1-P3, then decreased in P4 with relatively higher levels (>0.5) in almost all urban agglomerations. Furthermore, NO2 presented a stronger association with PM2.5/PM10 variation than CO; and PM2.5 with NO2/SO2 variation than PM10. In summary, the economic structure, lockdown measures and meteorological conditions could explain the noteworthy variations in different urban agglomerations. These results would be in great help for improving air quality in the post-epidemic periods.
Collapse
Affiliation(s)
- Yuting Bai
- School of Ecology and Environment, Inner Mongolia University, 010021, Hohhot, China
| | - Zichun Wang
- School of Ecology and Environment, Inner Mongolia University, 010021, Hohhot, China
| | - Fei Xie
- School of Ecology and Environment, Inner Mongolia University, 010021, Hohhot, China; Inner Mongolia Environmental Monitoring Center, 010011, Hohhot, China
| | - Le Cen
- School of Ecology and Environment, Inner Mongolia University, 010021, Hohhot, China
| | - Zhilei Xie
- Inner Mongolia Environmental Monitoring Center, 010011, Hohhot, China
| | - Xingjun Zhou
- Inner Mongolia Environmental Monitoring Center, 010011, Hohhot, China
| | - Jiang He
- School of Ecology and Environment, Inner Mongolia University, 010021, Hohhot, China; Institute of Environmental Geology, Inner Mongolia University, Hohhot, 010021, China
| | - Changwei Lü
- School of Ecology and Environment, Inner Mongolia University, 010021, Hohhot, China; Institute of Environmental Geology, Inner Mongolia University, Hohhot, 010021, China.
| |
Collapse
|