Changes in source contributions to the oxidative potential of PM_(2.5)in urban Xiamen,China  

作　　者：Jia-Min Li Si-Min Zhao Qi-Yu Miao Shui-Ping Wu Jie Zhang James J.Schwab 

机构地区：[1]Fujian Provincial Key Laboratory for Coastal Ecology and Environmental Studies,Xiamen University,Xiamen 361102,China [2]Center for Marine Environmental Chemistry and Toxicology,College of Environment and Ecology,Xiamen University,Xiamen 361102,China [3]Atmospheric Sciences Research Center,University at Albany,SUNY,Albany 12226,USA

出　　处：《Journal of Environmental Sciences》2025年第3期342-357,共16页环境科学学报(英文版)

基　　金：supported by the Science and Technology Program of Fujian Province,China(No.2023R1014002);the National Natural Science Foundation of China(No.41471390).

摘　　要：The toxicity of PM_(2.5)does not necessarily change synchronously with its mass concentration.In this study,the chemical composition(carbonaceous species,water-soluble ions,and metals)and oxidative potential(dithiothreitol assay,DTT)of PM_(2.5)were investigated in 2017/2018 and 2022 in Xiamen,China.The decrease rate of volume-normalized DTT(DTTv)(38%)was lower than that of PM_(2.5)(55%)between the two sampling periods.However,the mass-normalized DTT(DTTm)increased by 44%.Clear seasonal patterns with higher levels in winter were found for PM_(2.5),most chemical constituents and DTTv but not for DTTm.The large decrease in DTT activity(84%−92%)after the addition of EDTA suggested that watersoluble metals were the main contributors to DTT in Xiamen.The increased gap between the reconstructed and measured DTTv and the stronger correlations between the reconstructed/measured DTT ratio and carbonaceous species in 2022were observed.The decrease rates of the hazard index(32.5%)and lifetime cancer risk(9.1%)differed from those of PM_(2.5)and DTTv due to their different main contributors.The PMF-MLR model showed that the contributions(nmol/(min·m^(3)))of vehicle emission,coal+biomass burning,ship emission and secondary aerosol to DTTv in 2022 decreased by 63.0%,65.2%,66.5%,and 22.2%,respectively,compared to those in 2017/2018,which was consistent with the emission reduction of vehicle exhaust and coal consumption,the adoption of low-sulfur fuel oil used on board ships and the reduced production of WSOC.However,the contributions of dust+sea salt and industrial emission increased.

关 键 词：Chemical composition Oxidative potential Interannual change PMF-MLR Source apportionment 

分 类 号：F42[经济管理—产业经济]