International Joint Research Center for Persistent Toxic Substances (IJRC-PTS), State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin, 150090, China; Heilongjiang Provincial Key Laboratory of Polar Environment and Ecosystem (HPKL-PEE), Harbin, 150090, China.
School of Petrochemical Engineering, Lanzhou University of Technology, Lanzhou, 730050, China.
Environ Res. 2024 Jul 1;252(Pt 3):119067. doi: 10.1016/j.envres.2024.119067. Epub 2024 May 3.
Environmentally persistent free radicals (EPFRs) can pose exposure risks by inducing the generation of reactive oxygen species. As a new class of pollutants, EPFRs have been frequently detected in atmospheric particulate matters. In this study, the seasonal variations and sources of EPFRs in a severe cold region in Northeastern China were comprehensively investigated, especially for the high pollution events. The geomean concentration of EPFRs in the total suspended particle was 6.58 × 10 spins/m and the mean level in winter was one order of magnitude higher than summer and autumn. The correlation network analysis showed that EPFRs had significantly positive correlation with carbon component, K and PAHs, indicating that EPFRs were primarily emitted from combustion and pyrolysis process. The source appointment by the Positive Matrix Factorization (PMF) model indicated that the dominant sources in the heating season were coal combustion (48.4%), vehicle emission (23.1%) and biomass burning (19.4%), while the top three sources in the non-heating season were others (41.4%), coal combustion (23.7%) and vehicle emissions (21.2%). It was found that the high EPFRs in cold season can be ascribed to the extensive use of fossil fuel for heating demand; while the high EPFRs occurred in early spring were caused by the large-scale opening combustion of biomass. In summary, this study provided important basic information for better understanding the pollution characteristics of EPFRs, which suggested that the implementation of energy transformation and straw utilization was benefit for the control of EPFRs in severe cold region.
环境持久性自由基（EPFRs）可以通过诱导活性氧物质的生成来带来暴露风险。作为一类新型污染物，EPFRs 已在大气颗粒物中频繁检出。本研究全面调查了中国东北地区严寒地区 EPFRs 的季节性变化及其来源，尤其是在高污染事件期间。总悬浮颗粒物中 EPFRs 的几何平均值浓度为 6.58×10 自旋/m，冬季的平均水平比夏季和秋季高一个数量级。相关网络分析表明，EPFRs 与碳成分、K 和 PAHs 呈显著正相关，表明 EPFRs 主要来自燃烧和热解过程。正定矩阵因子分解（PMF）模型的源分配表明，供暖季节的主要来源是煤炭燃烧（48.4%）、车辆排放（23.1%）和生物质燃烧（19.4%），而在非供暖季节，前三大来源是其他来源（41.4%）、煤炭燃烧（23.7%）和车辆排放（21.2%）。研究发现，寒冷季节中 EPFRs 浓度较高可归因于化石燃料广泛用于取暖需求；而早春期间 EPFRs 浓度较高则是由于大规模的生物质露天燃烧所致。总之，本研究为更好地理解 EPFRs 的污染特征提供了重要的基础信息，表明实施能源转型和秸秆利用对于严寒地区 EPFRs 的控制是有益的。
