Sources and influences of atmospheric nonpolar organic compounds in Nanchang, central China: Full-year monitoring with a focus on winter pollution episodes

Wei Guo; Zicong Li; Ziyue Zhang; Renguo Zhu; Hongwei Xiao; Huayun Xiao

doi:10.1016/j.scitotenv.2023.169216

Sources and influences of atmospheric nonpolar organic compounds in Nanchang, central China: Full-year monitoring with a focus on winter pollution episodes

Sci Total Environ. 2024 Feb 20:912:169216. doi: 10.1016/j.scitotenv.2023.169216. Epub 2023 Dec 11.

Authors

Wei Guo¹, Zicong Li¹, Ziyue Zhang¹, Renguo Zhu¹, Hongwei Xiao², Huayun Xiao³

Affiliations

¹ School of Water Resources and environmental Engineering, East China University of Technology, Nanchang 330013, China; Jiangxi Province Key Laboratory of the Causes and Control of Atmospheric Pollution, East China University of Technology, Nanchang 330013, China.
² School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China.
³ School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: xiaohuayun@sjtu.edu.cn.

PMID: 38092198
DOI: 10.1016/j.scitotenv.2023.169216

Abstract

Nonpolar organic compounds (NPOCs) are found in atmospheric aerosols and have significant implications for environmental and human health. Although many studies have quantitatively estimated the sources of NPOCs in different cities, few have evaluated their main influencing factors (e.g., emissions and meteorological conditions) at relatively long (e.g., different seasons) and short timescales (e.g., several days during pollution episodes). A better understanding of this issue could optimise strategies for dealing with organic contamination in atmospheric particulate matter. NPOCs (including n-alkanes, PAHs and hopanes) in fine particulate matter (PM_2.5) were sampled daily at Nanchang, China, from 1 November 2020 to 31 October 2021. Analyses of specific biomarkers and diagnostic ratios indicate that the NPOCs mainly had anthropogenic sources. The quantitative estimates of a positive matrix factorization model show that fossil fuel and biomass combustion were the main sources of n-alkanes (contributing 64.8 %), while vehicle exhaust was the main source of PAHs (47.0 %) and hopanes (52.3 %). Seasonally, the contributions from coal and/or biomass combustion were higher in autumn and winter (40.2-56.3 %) than in spring and summer (25.7-44.3 %), while contributions from natural plants, petroleum volatilization and vehicle exhaust were higher in spring and summer (14.7-63.5 %) than in autumn and winter (8.1-48.9 %). Redundancy analysis shows that increased emissions, especially from coal and/or biomass combustion, are the main cause of increases in NPOCs, during both annual sampling periods and winter pollution episodes. Over the year, higher temperature and longer sunshine hours correspond to lower NPOC concentrations. In winter pollution episodes, increases in temperature and relative humidity correspond to increases in NPOC concentrations. Our results suggest that controlling primary emissions, especially from coal and biomass combustion, may be an effective way to prevent increases in NPOC concentrations.

Keywords: N-alkanes; NPOCs; Organic aerosols; PM(2.5); Source identification.

MeSH terms

Aerosols / analysis
Air Pollutants* / analysis
Alkanes / analysis
China
Coal / analysis
Environmental Monitoring
Humans
Organic Chemicals / analysis
Particulate Matter / analysis
Pentacyclic Triterpenes / analysis
Polycyclic Aromatic Hydrocarbons* / analysis
Seasons
Vehicle Emissions / analysis

Substances

Air Pollutants
Particulate Matter
Vehicle Emissions
Organic Chemicals
Coal
Aerosols
Polycyclic Aromatic Hydrocarbons
Pentacyclic Triterpenes
Alkanes