Key drivers of the oxidative potential of PM2.5 in Beijing in the context of air quality improvement from 2018 to 2022

Jinwen Li; Chenjie Hua; Li Ma; Kaiyun Chen; Feixue Zheng; Qingcai Chen; Xiaolei Bao; Juan Sun; Rongfu Xie; Federico Bianchi; Veli-Matti Kerminen; Tuukka Petäjä; Markku Kulmala; Yongchun Liu

doi:10.1016/j.envint.2024.108724

Key drivers of the oxidative potential of PM_2.5 in Beijing in the context of air quality improvement from 2018 to 2022

Environ Int. 2024 May:187:108724. doi: 10.1016/j.envint.2024.108724. Epub 2024 May 9.

Authors

Jinwen Li¹, Chenjie Hua¹, Li Ma¹, Kaiyun Chen¹, Feixue Zheng¹, Qingcai Chen², Xiaolei Bao³, Juan Sun⁴, Rongfu Xie⁵, Federico Bianchi⁶, Veli-Matti Kerminen⁶, Tuukka Petäjä⁶, Markku Kulmala⁷, Yongchun Liu⁸

Affiliations

¹ Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
² School of Environmental Science and Engineering, Shaanxi University of Science and Technology, Xi'an 710021, China.
³ Hebei Chemical & Pharmaceutical College, Shijiazhuang 050026, China.
⁴ Jiangsu Nanjing Environmental Monitoring Center, Nanjing 210019, China.
⁵ College of Ecology and Environment, Hainan University, Haikou 570228, China.
⁶ Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, Helsinki 00014, Finland.
⁷ Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China; Institute for Atmospheric and Earth System Research, Faculty of Science, University of Helsinki, Helsinki 00014, Finland.
⁸ Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, China. Electronic address: liuyc@buct.edu.cn.

PMID: 38735076
DOI: 10.1016/j.envint.2024.108724

Abstract

The mass concentration of atmospheric particulate matter (PM) has been continuously decreasing in the Beijing-Tianjin-Hebei region. However, health endpoints do not exhibit a linear correlation with PM mass concentrations. Thus, it is urgent to clarify the prior toxicological components of PM to further improve air quality. In this study, we analyzed the long-term oxidative potential (OP) of water-soluble PM_2.5, which is generally considered more effective in assessing hazardous exposure to PM in Beijing from 2018 to 2022 based on the dithiothreitol assay and identified the crucial drivers of the OP of PM_2.5 based on online monitoring of air pollutants, receptor model, and random forest (RF) model. Our results indicate that dust, traffic, and biomass combustion are the main sources of the OP of PM_2.5 in Beijing. The complex interactions of dust particles, black carbon, and gaseous pollutants (nitrogen dioxide and sulfur dioxide) are the main factors driving the OP evolution, in particular, leading to the abnormal rise of OP in Beijing in 2022. Our data shows that a higher OP is observed in winter and spring compared to summer and autumn. The diurnal variation of the OP is characterized by a declining trend from 0:00 to 14:00 and an increasing trend from 14:00 to 23:00. The spatial variation in OP of PM_2.5 was observed as the OP in Beijing is lower than that in Shijiazhuang, while it is higher than that in Zhenjiang and Haikou, which is primarily influenced by the distribution of black carbon. Our results are of significance in identifying the key drivers influencing the OP of PM_2.5 and provide new insights for advancing air quality improvement efforts with a focus on safeguarding human health in Beijing.

Keywords: Black carbon; Dust; Oxidative potential; PM(2.5); Synergistic effect.

MeSH terms

Air Pollutants* / analysis
Air Pollution* / statistics & numerical data
Beijing
Environmental Monitoring*
Oxidation-Reduction
Particulate Matter* / analysis
Quality Improvement
Seasons