Chemical characteristics,oxidative potential,and sources of PM_(2.5)in wintertime in Lahore and Peshawar,Pakistan  

作　　者：Mushtaq Ahmad Qing Yu Jing Chen Siming Cheng Weihua Qin Yuepeng Zhang 

机构地区：[1]State Key Joint Laboratory of Environment Simulation and Pollution Control,School of Environment,Beijing Normal University,Beijing 100875,China [2]Department of Environmental Sciences,University of Peshawar,Peshawar 25120,Pakistan

出　　处：《Journal of Environmental Sciences》2021年第4期148-158,共11页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.91543110);the fellowship granted by China Scholarship Council。

摘　　要：The chemical characteristics,oxidative potential,and sources of PM_(2.5)were analyzed at the urban sites of Lahore and Peshawar,Pakistan in February 2019.Carbonaceous species,water soluble ions,and metal elements were measured to investigate the chemical composition and sources of PM_(2.5).The dithiothreitol(DTT)consumption rate was measured to evaluate the oxidative potential of PM_(2.5).Both cities showed a high exposure risk of PM_(2.5)regarding its oxidative potential(DTT v).Carbonaceous and some of the elemental species of PM_(2.5)correlated well with DTT v in both Lahore and Peshawar.Besides,the DTT v of PM_(2.5)in Lahore showed significant positive correlation with most of the measured water soluble ions,however,ions were DTT-inactive in Peshawar.Due to the higher proportions of carbonaceous species and metal elements,Peshawar showed higher mass-normalized DTT activity of PM_(2.5)compared to Lahore although the average PM_(2.5)concentration in Peshawar was lower.The high concentrations of toxic metals also posed serious non-carcinogenic and carcinogenic risks to the residents of both cities.Principle component analysis coupled with multiple linear regression was applied to investigate different source contributions to PM_(2.5)and its oxidative potential.Mixed sources of traffic and road dust resuspension and coal combustion,direct vehicle emission,and biomass burning and formation of secondary aerosol were identified as the major sources of PM_(2.5)in both cities.The findings of this study provide important data for evaluation of the potential health risks of PM_(2.5)and for formulation of efficient control strategies in major cities of Pakistan.

关 键 词：Air pollution DTT Health risk Oxidative potential Source apportionment 

分 类 号：X513[环境科学与工程—环境工程]