OXIDATIVE POTENTIAL AND SOURCE APPORTIONMENT OF PM2.5 DURING SPRING IN CHANGZHOU
To explore health risks and sources of fine particles(PM2.5),we detected the oxidative potential(OP)of PM2.5 in spring in Changzhou using the dithiothreitol(DTT)method,and characterized it by DTTv(volume-normalized DTT consumption)and DTTm(mass-normalized DTT consumption).Two source apportionment methods including positive matrix factorization(PMF)and principal component analysis(PCA)combined with multiple linear regression(MLR),were used to resolve emission sources of DTTv.The results showed that the average daily DTTv and DTTm in PM2.5 were(0.83±0.09)nmol/(min·m3)and(12.52±4.22)pmol/(min·μg)during the sampling period,respectively,which were in the relatively lower exposure levels in China.Organic carbon,secondary ions(SO42-,NO3,and NH4),as well as characteristic elements of the traffic sources(Cu,Zn,etc.),correlated moderately with DTTv,suggesting both the secondary sources and traffic sources had some impact on PM exposure related to health.Source apportionment results from PMF showed that vehicle emission(40.1％)and secondary sources(35.6％)were more important contributors to DTTv in PM2.5 than dust sources(18.6％)and combustion sources(5.8％),and MLR-PCA source apportionment method further confirmed significant contribution to DTTv from vehicle emission and secondary sources.The results could provide theoretical and scientific guidance for precise prevention and control of air pollution and health effects.
PM2.5oxidative potentialmultiple linear regressionprincipal component analysispositive matrix factorization
NETL
NSTL
万方数据
