TY - JOUR
T1 - Influence of COVID-19 lockdown on the variation of organic aerosols
T2 - Insight into its molecular composition and oxidative potential
AU - Wang, Wei
AU - Zhang, Yanhao
AU - Cao, Guodong
AU - Song, Yuanyuan
AU - Zhang, Jing
AU - Li, Ruijin
AU - Zhao, Lifang
AU - Dong, Chuan
AU - Cai, Zongwei
N1 - Funding Information:
This work was supported by the National Natural Science Foundation of China ( 91843301 and 91543202 ) and National Key Research and Development Program Cooperation on Scientific and Technological Innovation in Hong Kong , Macau and Taiwan ( 2017YFE0191000 ). We thank Dr. Meilin Chen at the language center of Hong Kong Baptist University for her helping in improving the linguistic presentation of the manuscript.
Publisher Copyright:
© 2021 Elsevier Inc.
PY - 2022/4/15
Y1 - 2022/4/15
N2 - To prevent the transmission of the novel coronavirus disease 2019 (COVID-19), China adopted nationwide lockdown measures on January 25, 2020, leading to an evident diminution in the observed air pollutants. To investigate the influence of the lockdown on atmospheric chemistry, the specific molecular composition, oxidative potential of organic aerosols (OAs) in PM2.5 were studied using a high-resolution orbitrap mass spectrometry at a typical coal-combustion city, Linfen, in the North China Plain (NCP). The major air pollutants including PM2.5, PM10, SO2, NO2, and CO were observed to be diminished by 28.6–45.4%, while O3 was augmented by 52.5% during the lockdown compared to those before the lockdown. A significant decrease of oxygen-containing (CHO) compounds (24.7%) associated with anthropogenic acids was observed during the lockdown, implying a reduction in fossil fuel combustion. The coal-burning related sulfur-containing organosulfates (CHOS-) and nitrooxy-sulfates (CHONS-) have also shown attenuated in both their relative abundances and anthropogenic/biogenic ratios. Amine/amide-like CHON + components have decreased by 27.6%, while nitro/nitrooxy-containing CHON- compounds have only decreased by 7.1%. Multi-source nitrogen-containing (CHN) compounds have shown a moderate elimination of 24.0%, while the identified high-condensed azaarenes have fallen from 17.7% to 14.7%, implying a potential reduction in the health risk of OAs during quarantine. The measurement of OAs’ oxidative potential through dithiothreitol (DTT) assay has confirmed that as it had dropped from 0.88 nmol min−1 m−3 to 0.80 nmol min−1 m−3. High correlations were observed between the abundance of OA subgroups with the concentration of PM2.5 after the execution of the lockdown, suggesting a potential elevation in the contribution of organic components to the total PM2.5 level. Our study provides insightful compositional and health-related information in the variation of OAs during the lockdown period and attests to the validity of joint-control strategy in controlling the level and health risks of numerous atmospheric pollutants.
AB - To prevent the transmission of the novel coronavirus disease 2019 (COVID-19), China adopted nationwide lockdown measures on January 25, 2020, leading to an evident diminution in the observed air pollutants. To investigate the influence of the lockdown on atmospheric chemistry, the specific molecular composition, oxidative potential of organic aerosols (OAs) in PM2.5 were studied using a high-resolution orbitrap mass spectrometry at a typical coal-combustion city, Linfen, in the North China Plain (NCP). The major air pollutants including PM2.5, PM10, SO2, NO2, and CO were observed to be diminished by 28.6–45.4%, while O3 was augmented by 52.5% during the lockdown compared to those before the lockdown. A significant decrease of oxygen-containing (CHO) compounds (24.7%) associated with anthropogenic acids was observed during the lockdown, implying a reduction in fossil fuel combustion. The coal-burning related sulfur-containing organosulfates (CHOS-) and nitrooxy-sulfates (CHONS-) have also shown attenuated in both their relative abundances and anthropogenic/biogenic ratios. Amine/amide-like CHON + components have decreased by 27.6%, while nitro/nitrooxy-containing CHON- compounds have only decreased by 7.1%. Multi-source nitrogen-containing (CHN) compounds have shown a moderate elimination of 24.0%, while the identified high-condensed azaarenes have fallen from 17.7% to 14.7%, implying a potential reduction in the health risk of OAs during quarantine. The measurement of OAs’ oxidative potential through dithiothreitol (DTT) assay has confirmed that as it had dropped from 0.88 nmol min−1 m−3 to 0.80 nmol min−1 m−3. High correlations were observed between the abundance of OA subgroups with the concentration of PM2.5 after the execution of the lockdown, suggesting a potential elevation in the contribution of organic components to the total PM2.5 level. Our study provides insightful compositional and health-related information in the variation of OAs during the lockdown period and attests to the validity of joint-control strategy in controlling the level and health risks of numerous atmospheric pollutants.
KW - Covid-19 epidemic
KW - Molecular composition
KW - Orbitrap MS
KW - Organic aerosols
KW - Oxidative potential
UR - http://www.scopus.com/inward/record.url?scp=85122134817&partnerID=8YFLogxK
U2 - 10.1016/j.envres.2021.112597
DO - 10.1016/j.envres.2021.112597
M3 - Journal article
C2 - 34954148
AN - SCOPUS:85122134817
SN - 0013-9351
VL - 206
JO - Environmental Research
JF - Environmental Research
M1 - 112597
ER -
