Impact of the COVID-19 lockdown on air pollution in an industrial city in Northeastern China

    Xueyan Wang Affiliation
    ; Yuqing Wang Affiliation
    ; Yiran Zhao Affiliation
    ; Meijin Tian Affiliation
    ; Xinmeng Wu Affiliation
    ; Yongzhen Zhang Affiliation
    ; Feng Gao Affiliation
    ; Junjiao Sun Affiliation
    ; Xiaoqing Wei Affiliation
    ; Xiuying Yang Affiliation
    ; Xiaohan Qu Affiliation


Many studies in China investigated how the lockdown following the coronavirus disease 2019 substantially affected air quality; however, few were conducted in Northeastern China. Here, the changes in six criteria air pollutants, including particulate matter (PM10 and PM2.5), nitrogen dioxide (NO2), carbon monoxide (CO), sulfur dioxide (SO2), and ozone (O3), were investigated in Shenyang from January to May 2015–2020. Compared with the pre-lockdown, the mass concentrations of PM2.5, PM10, SO2, NO2, and CO during the lockdown decreased by 40.3% to 48.6%, indicating a positive impact of lockdown policies on reducing pollutant emissions. The responses of PM2.5, PM10, and CO to the lockdown measures in downtown areas were more sensitive than in the suburbs. However, the O3 concentration showed the opposite trend, attributed to the drop in NOx and particulate matters. Compared to the same period in 2015–2019, the proportion of days with good air quality increased from 63.2% to 77.2% during the lockdown and Shenyang experienced no severe pollution. Our results suggest that reducing human activities can improve air quality; however, coordinated control policies of O3, PM2.5, and NO2 are imperative. 

Keyword : novel coronavirus, air quality index, spatiotemporal distribution, lockdown, particulate matter, nitrogen dioxide, carbon monoxide, sulfur dioxide, ozone

How to Cite
Wang, X., Wang, Y., Zhao, Y., Tian, M., Wu, X., Zhang, Y., Gao, F., Sun, J., Wei, X., Yang, X., & Qu, X. (2023). Impact of the COVID-19 lockdown on air pollution in an industrial city in Northeastern China. Journal of Environmental Engineering and Landscape Management, 31(3), 219–231.
Published in Issue
Sep 4, 2023
Abstract Views
PDF Downloads
SM Downloads
Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.


Adam, M. G., Tran, P. T. M., & Balasubramanian, R. (2021). Air quality changes in cities during the COVID-19 lockdown: A critical review. Atmospheric Research, 264, 105823.

Allison, L. S. (2020). Role of the terrestrial biosphere in atmospheric chemistry and climate. Accounts of Chemical Research, 53(7), 1260–1268.

Bagherinia, M., Bodaghpour, S., Karimi, N., Ghasempour, F., Bilal, M., & Mhawish, A. (2023). Spatio-temporal air quality assessment in Tehran, Iran, during the COVID-19 lockdown periods. Geocarto International, 38(1), 2169374.

Bao, R., & Zhang, A. (2020). Does lockdown reduce air pollution? Evidence from 44 cities in northern China. Science of the Total Environment, 731, 139052.

Cai, W., Wang, H., Wu, C., Lu, K., Peng, Z., & He, H. (2021). Characterizing the interruption-recovery patterns of urban air pollution under the COVID-19 lockdown in China. Building and Environment, 205, 108231.

Cao, X., Liu, X., Hadiatullah, H., Xu, Y., Zhang, X., Cyrys, J., Zimmermann, R., & Adam, T. (2022). Investigation of COVID-19-related lockdowns on the air pollution changes in Augsburg in 2020, Germany. Atmospheric Pollution Research, 13(9), 101536.

Chen, Y., Bai, Y., Liu, H., Alatalo, J. M., & Jiang, B. (2020). Temporal variations in ambient air quality indicators in Shanghai municipality, China. Scientific Reports, 10(1), 11350.

Chen, Z., Hao, X., Zhang, X., & Chen, F. (2021). Have traffic restrictions improved air quality? A shock from COVID-19. Journal of Cleaner Production, 279, 123622.

Chu, B., Zhang, S., Liu, J., Ma, Q., & He, H. (2021). Significant concurrent decrease in PM2.5 and NO2 concentrations in China during COVID-19 epidemic. Journal of Environmental Sciences, 99, 346–353.

Coates, J., Mar, K. A., Ojha, N., & Butler, T. M. (2016). The influence of temperature on ozone production under varying NOx conditions – a modelling study. Atmospheric Chemistry and Physics, 16(18), 11601–11615.

Cooper, M. J., Martin, R. V., Hammer, M. S., Levelt, P. F., Veefkind, P., Lamsal, L. N., Krotkov, N. A., Brook, J. R., & McLinden, C. A. (2022). Global fine-scale changes in ambient NO2 during COVID-19 lockdowns. Nature, 601(7893), 380–387.

Dong, X., Zheng, X., Wang, C., Zeng, J., & Zhang, L. (2022). Air pollution rebound and different recovery modes during the period of easing COVID-19 restrictions. Science of the Total Environment, 843, 156942.

Filonchyk, M., & Peterson, M. (2020). Air quality changes in Shanghai, China, and the surrounding urban agglomeration during the COVID-19 lockdown. Journal of Geovisualization and Spatial Analysis, 4(2), 22.

Gao, C., Zhang, F., Fang, D., Wang, Q., & Liu, M. (2023). Spatial characteristics of change trends of air pollutants in Chinese urban areas during 2016–2020: The impact of air pollution controls and the COVID-19 pandemic. Atmospheric Research, 283, 106539.

Grange, S. K., Lee, J. D., Drysdale, W. S., Lewis, A. C., Hueglin, C., Emmenegger, L., & Carslaw, D. C. (2021). COVID-19 lockdowns highlight a risk of increasing ozone pollution in European urban areas. Atmospheric Chemistry and Physics, 21(5), 4169–4185.

Guo, Q., He, Z., & Wang, Z. (2023). Change in air quality during 2014–2021 in Jinan City in China and its influencing factors. Toxics, 11(3), 210.

Hammad, H. M., Nauman, H. M. F., Abbas, F., Jawad, R., Far­had, W., Shahid, M., Bakhat, H. F., Farooque, A. A., Mubeen, M., Fahad, S., & Cerda, A. (2023). Impacts of COVID-19 pandemic on environment, society, and food security. Environmental Science and Pollution Research.

Han, J., Yin, J., Wu, X., Wang, D., & Li, C. (2023). Environment and COVID-19 incidence: A critical review. Journal of Environmental Sciences, 124, 933–951.

Harapan, H., Itoh, N., Yufika, A., Winardi, W., Keam, S., Te, H., Megawati, D., Hayati, Z., Wagner, A. L., & Mudatsir, M. (2020). Coronavirus disease 2019 (COVID-19): A literature review. Journal of Infection and Public Health, 13(5), 667–673.

Hasnain, A., Hashmi, M. Z., Bhatti, U. A., Nadeem, B., Wei, G., Zha, Y., & Sheng, Y. (2021). Assessment of air pollution before, during and after the COVID-19 pandemic lockdown in Nanjing, China. Atmosphere, 12, 743.

He, G., Pan, Y., & Tanaka, T. (2020). The short-term impacts of COVID-19 lockdown on urban air pollution in China. Nature Sustainability, 3(12), 1005–1011.

Huang, C., Wang, T., Niu, T., Han, J., Li, M., Zhang, N., Liu, H., & Ma, C. (2021). Study on the causes of heavy pollution in Shenyang based on the contribution of natural conditions, physical processes, and anthropogenic emissions. Atmospheric Pollution Research, 12(4), 101224.

Huang, X., Ding, A., Gao, J., Zheng, B., Zhou, D., Qi, X., Tang, R., Wang, J., Ren, C., Nie, W., Chi, X., Xu, Z., Chen, L., Li, Y., Che, F., Pang, N.,Wang, H., Tong, D., Qin, W., ... He, K. (2020). Enhanced secondary pollution offset reduction of primary emissions during COVID-19 lockdown in China. National Science Review, 8(2), nwaa137.

Huang, Y., & Li, R. (2022). The lockdown, mobility, and spatial health disparities in COVID-19 pandemic: A case study of New York City. Cities, 122, 103549.

Jia, H., Zang, S., Zhang, L., Yakovleva, E., Sun, H., & Sun, L. (2023). Spatiotemporal characteristics and socioeconomic factors of PM2.5 heterogeneity in mainland China during the COVID-19 epidemic. Chemosphere, 331, 138785.

Kulkarni, P. S., Bortoli, D., & Silva, A. M. (2013). Nocturnal surface ozone enhancement and trend over urban and suburban sites in Portugal. Atmospheric Environment, 71, 251–259.

Kumar, A., Dhakhwa, S., & Dikshit, A. K. (2022). Comparative evaluation of fitness of interpolation techniques of ArcGIS using leave-one-out scheme for air quality mapping. Journal of Geovisualization and Spatial Analysis, 6(1), 9.

Le, T., Wang, Y., Liu, L., Yang, J., Yung, Y. L., Li, G., & Seinfeld, J. H. (2020). Unexpected air pollution with marked emission reductions during the COVID-19 outbreak in China. Science, 369(6504), 702–706.

Li, D., & Lasenby, J. (2023). Investigating impacts of COVID-19 on urban mobility and emissions. Cities, 135, 104246.

Li, K., Jacob, D. J., Liao, H., Shen, L., Zhang, Q., & Bates, K. H. (2019). Anthropogenic drivers of 2013–2017 trends in summer surface ozone in China. Proceedings of the National Academy of Sciences of the United States of America, 116(2), 422–427.

Li, K., Ni, R., Jiang, T., Tian, Y., Zhang, X., Li, C., & Xie, C. (2022). The regional impact of the COVID-19 lockdown on the air quality in Ji’nan, China. Scientific Reports, 12(1), 12099.

Li, L., Li, Q., Huang, L., Wang, Q., Zhu, A., Xu, J., Liu, Z., Li, H., Shi, L., Li, R., Azari, M., Wang, Y., Zhang, X., Liu, Z., Zhu, Y., Zhang, K., Xue, S., Ooi, M. C. G., Zhang, D., & Chan, A. (2020). Air quality changes during the COVID-19 lockdown over the Yangtze River Delta Region: An insight into the impact of human activity pattern changes on air pollution variation. Science of the Total Environment, 732, 139282.

Liang, Q., Liu, S., Yin, J., Han, Q., Zhang, W., & Niu, J. (2023). Spatial–temporal characteristics and influencing mechanisms of air quality index by considering COVID-19 in Yunnan, Southeastern Tibetan Plateau. Atmosphere, 14(2), 378.

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. (2020). Driving forces of changes in air quality during the COVID-19 lockdown period in the Yangtze River Delta Region, China. Environmental Science and Technology Letters, 7(11), 779–786.

Llaguno-Munitxa, M., & Bou-Zeid, E. (2023). Role of vehicular emissions in urban air quality: The COVID-19 lockdown experiment. Transportation Research Part D: Transport and Environment, 115, 103580.

Luo, L., Bai, X., Lv, Y., Liu, S., Guo, Z., Liu, W., Hao, Y., Sun, Y., Hao, J., Zhang, K., Zhao, H., Lin S., Zhao, S., Xiao, Y., Yang, J., & Tian, H. (2022). Exploring the driving factors of haze events in Beijing during Chinese New Year holidays in 2020 and 2021 under the influence of COVID-19 pandemic. Science of the Total Environment, 859(1), 160172.

Ma, Q., Wang, J., Xiong, M., & Zhu, L. (2023). Air Quality Index (AQI) did not improve during the COVID-19 lockdown in Shanghai, China, in 2022, based on ground and TROPOMI observations. Remote Sensing, 15(5), 1295.

Ma, Y., Wang, M., Wang, S., Wang, Y., Feng, L., & Wu, K. (2021). Air pollutant emission characteristics and HYSPLIT model analysis during heating period in Shenyang, China. Environmental Monitoring and Assessment, 193(1), 9.

Mamtimin, A., Wang, Y., Zhao, T., Sayit, H., Yang, F., Huo, W., Zhou, C., & Gao, J. (2022). Impacts of winter and summer COVID-19 lockdowns on urban air quality in Urumqi, Northwest China. Frontiers in Environmental Science, 10, 910579.

Mo, Z., Huang, J., Chen, Z., Zhou, B., Zhu, K., Liu, H., Mu, Y., Zhang, D., & Wang, S. (2021). Cause analysis of PM2.5 pollution during the COVID-19 lockdown in Nanning, China. Scientific Reports, 11(1), 1–13.

Pushpawela, B., Shelton, S., Liyanage, G., Jayasekara, S., Rajapaksha, D., Jayasundara, A., & Jayasuriya, L. D. (2023). Changes of air pollutants in urban cities during the COVID-19 lockdown-Sri Lanka. Aerosol and Air Quality Research, 23(3), 220223.

Ren, Y., Guan, X., Zhang, Q., Li, L., Tao, C., Ren, S., Wang, Q., & Wang, W. (2023). A machine learning-based study on the impact of COVID-19 on three kinds of pollution in Beijing-Tianjin-Hebei region. Science of the Total Environment, 884, 163190.

Rupakheti, D., Yin, X., Rupakheti, M., Zhang, Q., Li, P., Rai, M., & Kang, S. (2021). Spatio-temporal characteristics of air pollutants over Xinjiang, northwestern China. Environmental Pollution, 268, 115907.

Sbai, S. E., Mejjad, N., Norelyaqine, A., & Bentayeb, F. (2021). Air quality change during the COVID-19 pandemic lockdown over the Auvergne-Rhone-Alpes region, France. Air Quality, Atmosphere and Health, 14(5), 617–628.

Sekar, A., Jasna, R. S., Binoy, B. V., Mohan, P., & Kuttiparichel Varghese, G. (2023). Air quality change and public perception during the COVID-19 lockdown in India. Gondwana Research, 114, 15–29.

Sharma, S., Zhang, M., Anshika, Gao, J., Zhang, H., & Kota, S. H. (2020). Effect of restricted emissions during COVID-19 on air quality in India. Science of the Total Environment, 728, 138878.

Sicard, P., De Marco, A., Agathokleous, E., Feng, Z., Xu, X., Paoletti, E., Rodriguez, J. J. D., & Calatayud, V. (2020). Amplified ozone pollution in cities during the COVID-19 lockdown. Science of the Total Environment, 735, 139542.

Singh, V., Singh, S., Biswal, A., Kesarkar, A.P., Mor, S., & Ravind­ra, K. (2020). Diurnal and temporal changes in air pollution during COVID-19 strict lockdown over different regions of India. Environmental Pollution, 266(Part 3), 115368.

Song, Y., Li, Z., Liu, J., Yang, T., Zhang, M., & Pang, J. (2021). The effect of environmental regulation on air quality in China: A natural experiment during the COVID-19 pandemic. Atmospheric Pollution Research, 12(4), 21–30.

Vadiati, M., Ghasemi, L., Samani, S., Islam, M. A., Ahmadi, A., Khaleghi, S., Movarej, M., Gorgij, A. D., Kisi, O., Davoodi, S., Dhama, K., Tiwari, A., & Bhattacharya, P. (2023). A sustainable trend in COVID-19 research: An environmental perspective. Frontiers in Environmental Science, 11, 1104679.

Wang, H., Miao, Q., Shen, L., Yang, Q., Wu, Y., & Wei, H. (2021a). Air pollutant variations in Suzhou during the 2019 novel coronavirus (COVID-19) lockdown of 2020: High time-resolution measurements of aerosol chemical compositions and source apportionment. Environmental Pollution, 271, 116298.

Wang, J., Shi, W., Xue, K., Wu, T., & Fang, C. (2023). Analysis of the impact of meteorological factors on ambient air quality during the COVID-19 lockdown in Jilin City in 2022. Atmosphere, 14(2), 400.

Wang, L., Li, M., Yu, S., Chen, X., Li, Z., Zhang, Y., Jiang, L., Xia, Y., Li, J., Liu, W., Li, P., Lichtfouse, E., Rosenfeld, D., & Seinfeld, J. H. (2020c). Unexpected rise of ozone in urban and rural areas, and sulfur dioxide in rural areas during the coronavirus city lockdown in Hangzhou, China: implications for air quality. Environmental Chemistry Letters, 18(368), 1713–1723.

Wang, L., Zhao, W., Luo, P., He, Q., Zhang, W., Dong, C., & Zhang, Y. (2024). Environmentally persistent free radicals in PM2.5 from a typical Chinese industrial city during COVID-19 lockdown: The unexpected contamination level variation. Journal of Environmental Sciences, 135, 424–432.

Wang, M., Liu, F., & Zheng, M. (2021b). Air quality improvement from COVID-19 lockdown: evidence from China. Air Quality, Atmosphere and Health, 14(4), 591–604.

Wang, P., Chen, K., Zhu, S., Wang, P., & Zhang, H. (2020a). Severe air pollution events not avoided by reduced anthropogenic activities during COVID-19 outbreak. Resources, Conservation and Recycling, 158, 104814.

Wang, X., & Zhang, R. (2020). How did air pollution change during the COVID-19 outbreak in China? Bulletin of the American Meteorological Society, 101(10), E1645–E1652.

Wang, Y., & Ge, Q. (2023). The positive impact of the Omicron pandemic lockdown on air quality and human health in cities around Shanghai. Environment, Development and Sustainability.

Wang, Y., Duan, X., Liang, T., Wang, L., & Wang, L. (2022). Analysis of spatio-temporal distribution characteristics and socioeconomic drivers of urban air quality in China. Chemo­sphere, 291, 132799.

Wang, Y., Gao, W., Wang, S., Song, T., Gong, Z., Ji, D., Wang, L., Liu, Z., Tang, G., Huo, Y., Tian, S., Li, J., Li, M., Yang, Y., Chu, B., Petäjä, T., Kerminen, V. M., He, H., Hao, J., ... Zhang, Y. (2020d). Contrasting trends of PM2.5 and surface-ozone concentrations in China from 2013 to 2017. National Science Review, 7(8), 1331–1339.

Wang, Y., Wen, Y., Wang, Y., Zhang, S., Zhang, K. M., Zheng, H., Xing, J., Wu, Y., & Hao, J. (2020b). Four-month changes in air quality during and after the COVID-19 lockdown in six megacities in China. Environmental Science and Technology Letters, 7(11), 802–808.

Wang, Z., Li, Y., Chen, T., Li, L., Liu, B., Zhang, D., Sun, F., Wei, Q., Jiang, L., & Pan, L. (2015). Changes in atmospheric composition during the 2014 APEC conference in Beijing. Journal of Geophysical Research: Atmospheres, 120(24), 12695–12707.

Wong, Y. J., Yeganeh, A., Chia, M. Y., Shiu, H. Y., Ooi, M. C. G., Chang, J. H. W., Shimizu, Y., Ryosuke, H., Try, S., & Elbeltagi, A. (2023). Quantification of COVID-19 impacts on NO2 and O3: Systematic model selection and hyperparameter optimization on AI-based meteorological-normalization methods. Atmospheric Environment, 301, 119677.

World Health Organization. (2020). Introduction to COVID-19: Methods for detection, prevention, response and control.

Xiao, K., Wang, Y., Wu, G., Fu, B., & Zhu, Y. (2018). Spatiotemporal characteristics of air pollutants (PM10, PM2.5, SO2, NO2, O3, and CO) in the inland basin city of Chengdu, southwest China. Atmosphere, 9(2), 74.

Xu, K., Cui, K., Young, L. H., Wang, Y. F., Hsieh, Y. K., Wan, S., & Zhang, J. (2020). Air quality index, indicatory air pollutants and impact of COVID-19 event on the air quality near central China. Aerosol and Air Quality Research, 20(6), 1204–1221.

Yang, H., Peng, Q., Zhou, J., Song, G., & Gong, X. (2020). The unidirectional causality influence of factors on PM2.5 in Shenyang city of China. Scientific Reports, 10(1), 8403.

Yang, J., Ji, Q., Pu, H., Dong, X., & Yang, Q. (2023). How does COVID-19 lockdown affect air quality: Evidence from Lanzhou, a large city in Northwest China. Urban Climate, 49, 101533.

Yao, Y., Wang, Y., Yu, H., & Qin, H. (2021). Analysis on the influencing factors of air quality during the Spring Festival in Beijing in 2020. Environment, Development and Sustainability, 46(2), 107–114.

Yin, H., Liu, C., Hu, Q., Liu, T., Wang, S., Gao, M., Xu, S., Zhang, C., & Su, W. (2021). Opposite impact of emission reduction during the COVID-19 lockdown period on the surface concentrations of PM2.5 and O3 in Wuhan, China. Environmental Pollution, 289, 117899.

Zeng, J., & Wang, C. (2022). Temporal characteristics and spatial heterogeneity of air quality changes due to the COVID-19 lockdown in China. Resources, Conservation and Recycling, 181, 106223.

Zhang, C., & Stevenson, D. (2022). Characteristic changes of ozone and its precursors in London during COVID-19 lockdown and the ozone surge reason analysis. Atmospheric Environment, 273, 118980.

Zhang, H., Wang, Y., Hu, J., Ying, Q., & Hu, X. M. (2015). Relationships between meteorological parameters and criteria air pollutants in three megacities in China. Environmental Research, 140, 242–254.

Zhang, Q., Mao, X., Wang, Z., Tan, Y., Zhang, Z., Wu, Y., & Gao, Y. (2023). Impact of the emergency response to COVID-19 on air quality and its policy implications: Evidence from 290 cities in China. Environmental Science & Policy, 145, 50–59.

Zhao, H., Zheng, Y., & Li, C. (2018). Spatiotemporal distribution of PM2.5 and O3 and their interaction during the summer and winter seasons in Beijing, China. Sustainability, 10(12), 4519.

Zhao, S., Yu, Y., Yin, D., He, J., Liu, N., Qu, J., & Xiao, J. (2016). Annual and diurnal variations of gaseous and particulate pollutants in 31 provincial capital cities based on in situ air quality monitoring data from China National Environmental Monitoring Center. Environment International, 86, 92–106.

Zhao, Y., Zhang, K., Xu, X., Shen, H., Zhu, X., Zhang, Y., Hu, Y., & Shen, G. (2020). Substantial changes in nitrogen dioxide and ozone after excluding meteorological impacts during the COVID-19 outbreak in mainland China. Environmental Science and Technology Letters, 7(6), 402–408.

Zheng, B., Zhang, Q., Geng, G., Chen, C., Shi, Q., Cui, M., Lei, Y., & He, K. (2021). Changes in China’s anthropogenic emissions and air quality during the COVID-19 pandemic in 2020. Earth System Science Data, 13(6), 2895–2097.

Zheng, H., Kong, S., Chen, N., Yan, Y., Liu, D., Zhu, B., Xu, K., Cao, W., Ding, Q., Lan, B., Zhang, Z., Zheng, M., Fan, Z., Cheng, Y., Zheng, S., Yao, L., Bai, Y., Zhao, T., & Qi, S. (2020). Significant changes in the chemical compositions and sources of PM2.5 in Wuhan since the city lockdown as COVID-19. Science of the Total Environment, 739, 140000.

Zhu, Y., Xie, J., Huang, F., & Cao, L. (2020). The mediating effect of air quality on the association between human mobility and COVID-19 infection in China. Environmental Research, 189, 109911.