Air quality improvement in response to intensified control strategies in Beijing during 2013-2019

Wenjun Li; Longyi Shao; Wenhua Wang; Hong Li; Xinming Wang; Yaowei Li; Weijun Li; Tim Jones; Daizhou Zhang

doi:10.1016/j.scitotenv.2020.140776

Air quality improvement in response to intensified control strategies in Beijing during 2013-2019

Sci Total Environ. 2020 Nov 20:744:140776. doi: 10.1016/j.scitotenv.2020.140776. Epub 2020 Jul 12.

Authors

Wenjun Li¹, Longyi Shao², Wenhua Wang¹, Hong Li³, Xinming Wang⁴, Yaowei Li¹, Weijun Li⁵, Tim Jones⁶, Daizhou Zhang⁷

Affiliations

¹ State Key Laboratory of Coal Resources and Safe Mining, College of Geoscience and Survey Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China.
² State Key Laboratory of Coal Resources and Safe Mining, College of Geoscience and Survey Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China. Electronic address: shaol@cumtb.edu.cn.
³ State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
⁴ State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China.
⁵ Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou 310027, China.
⁶ School of Earth and Ocean Sciences, Cardiff University, Museum Avenue, Cardiff CF10 3YE, UK.
⁷ Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, Kumamoto 862-8502, Japan.

PMID: 32721667
DOI: 10.1016/j.scitotenv.2020.140776

Abstract

Beijing's air pollution has become of increasing concern in recent years. The central and municipal governments have issued a series of laws, regulations, and strategies to improve ambient air quality. The "Clean Air Action" issued in 2013 and the "Comprehensive Action" issued in 2017 largely addressed this concern. In this study, we assessed the effectiveness of the two action plans by environmental monitoring data and evaluated the influencing factors including meteorology, pollutant emissions, and energy structure. The spatial distributions of air pollutants were analyzed using the Kriging interpolation method. The Principal Component Analysis-Multiple Nonlinear Regression (PCA-MNLR) model was applied to estimate the effects of meteorological factors. The results have shown that Beijing's air quality had a measurable improvement over 2013-2019. "Good air quality" days had the highest increases, and "hazardous air quality" days had the most decreases. SO₂ decreased most, followed by CO, PM_2.5, PM₁₀, and NO₂ in descending order, but O₃ showed a fluctuant increase. The "Comprehensive Action" was more effective than the "Clean Air Action" in reducing heavy pollution days during the heating period. The meteorological normalized values of the main pollutants were lower than the observation data during 2013-2016. However, the observed values became lower than the normalized values after 2017, which indicated beneficial weather conditions in 2017 and afterwards. The emissions of SO₂ and dust significantly decreased while NOx had a slight decrease, and the energy structure changed with a dramatic decrease in coal consumption and an obvious increase in the use of natural gas and electricity. The significant reduction of coal-fired emissions played a dominant role in improving Beijing's air quality, and vehicle emission control should be further enhanced. The results demonstrated the effectiveness of the two action plans and the experience in Beijing should have potential implications for other areas and nations suffering from severe air pollution.

Keywords: Air quality; Beijing; Clean air action; Comprehensive action; Effectiveness evaluation; PCA-MNLR model.

Publication types

Review