Insights into PM2.5 pollution of four small and medium-sized cities in Chinese representative regions: Chemical compositions, sources and health risks

Jiayuan Liu; Tong Ma; Jianhua Chen; Xing Peng; Yuechong Zhang; Yali Wang; Jianfei Peng; Guoliang Shi; Yuting Wei; Jian Gao

doi:10.1016/j.scitotenv.2024.170620

Insights into PM_2.5 pollution of four small and medium-sized cities in Chinese representative regions: Chemical compositions, sources and health risks

Sci Total Environ. 2024 Mar 25:918:170620. doi: 10.1016/j.scitotenv.2024.170620. Epub 2024 Feb 5.

Authors

Jiayuan Liu¹, Tong Ma², Jianhua Chen³, Xing Peng⁴, Yuechong Zhang³, Yali Wang³, Jianfei Peng¹, Guoliang Shi⁵, Yuting Wei⁵, Jian Gao⁶

Affiliations

¹ Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
² Chinese Research Academy of Environmental Sciences, Beijing 100012, China. Electronic address: ma.tong@craes.org.cn.
³ Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
⁴ Laboratory of Atmospheric Observation Supersite, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
⁵ State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China.
⁶ Chinese Research Academy of Environmental Sciences, Beijing 100012, China. Electronic address: gaojian@craes.org.cn.

PMID: 38320696
DOI: 10.1016/j.scitotenv.2024.170620

Abstract

Fine particles (PM_2.5) pollution is still a severe issue in some cities in China, where the chemical characteristics of PM_2.5 remain unclear due to limited studies there. Herein, we focused on PM_2.5 pollution in small and medium-sized cities in key urban agglomerations and conducted a comprehensive study on the PM_2.5 chemical characteristics, sources, and health risks. In the autumn and winter of 2019-2020, PM_2.5 samples were collected simultaneously in four small and medium-sized cities in four key regions: Dingzhou (Beijing-Tianjin-Hebei region), Weinan (Fenwei Plain region), Fukang (Northern Slope of the Tianshan Mountain region), and Bozhou (Yangtze River Delta region). The results showed that secondary inorganic ions (43.1 %-67.0 %) and organic matter (OM, 8.6 %-36.4 %) were the main components of PM_2.5 in all the cities. Specifically, Fukang with the most severe PM_2.5 pollution had the highest proportion of SO₄^2- (31.2 %), while the dominant components in other cities were NO₃^- and OM. The Multilinear Engine 2 (ME2) analysis identified five sources of PM_2.5 in these cities. Coal combustion contributed most to PM_2.5 in Fukang, but secondary sources in other cities. Combined with chemical characteristics and ME2 analysis, it was preliminarily determined that the primary emission of coal combustion had an important contribution to high SO₄^2- in Fukang. Potential source contribution function (PSCF) analysis results showed that regional transport played an important role in PM_2.5 in Dingzhou, Weinan and Bozhou, while PM_2.5 in Fukang was mainly affected by short-range transport from surrounding areas. Finally, the health risk assessment indicated Mn was the dominant contributor to the total non-carcinogenic risks and Cr had higher carcinogenic risks in all cities. The findings provide a scientific basis for formulating more effective abatement strategies for PM_2.5 pollution.

Keywords: Chemical composition; Fine particles; Key regions; Primary sulfate; Small and medium-sized cities; Sources.

MeSH terms

Air Pollutants* / analysis
Air Pollution* / analysis
China
Cities
Coal / analysis
Environmental Monitoring / methods
Particulate Matter / analysis
Seasons

Substances

Air Pollutants
Particulate Matter
Coal