| Parent polycyclic aromatic hydrocarbons(PPAHs)and their derivatives are a class of persistent organic pollutants with carcinogenic,teratogenic and mutagenic properties.They are ubiquitous commonly found in the environment,and some of their derivatives are more toxic than PPAHs.The eastern coastal region of China is one of the regions with the highest PAHs emissions in China.Therefore,understanding the pollution sources and health risks of atmospheric PPAHs and their derivatives in eastern coastal cities of China is an important basis for the prevention and air pollution control.In this study,we collected and measured atmospheric PM1.0 and PM2.5 samples from urban and coastal background sampling sites in the eastern coastal region,and analyzed 18 parent PAHs(∑18PPAHs),17 nitrated PAHs(∑17NPAHs),7 oxygenated PAHs(∑7OPAHs),8 chlorinated PAHs(∑8ClPAHs)and 13 brominated PAHs(∑13BrPAHs).The temporal distribution,molecular composition,relationships with atmospheric pollutants and meteorological condition,pollution sources and health risk assessment of PPAHs and their derivatives in winter and summer in the study area were studied.The study showed that the annual concentrations of PPAHs in PM1.0 and PM2.5 in the study area were 36.43±48.30 ng/m3 and 50.43±63.18 ng/m3,respectively.The average concentration of PPAHs and their derivatives(the sum of all 63 compounds)in PM1.0 samples accounted for 75.57%of the PAHs concentration in PM2.5 samples.The average concentration of PM1.0-and PM2.5-bound to PPAHs in winter was 114.70 times higher than those in summer,and their derivatives was 27.51 times higher.Both the combined concentrations of the 18 PPAHs and the combined concentrations of the 45 derivatives were higher in the coastal city compared to the background site during the winter(1.90 and 1.48 times,respectively),but they were comparable during the summer.PPAHs and their derivatives in PM1.0 and PM2.5 were positively correlated with PM2.5,PM10,SO2,NO2 and CO(p<0.05),but negatively correlated with O3(p<0.01).PPAHs and their derivatives were mainly positively correlated with air pressure(p<0.01),but negatively correlated with air temperature and relative humidity(p<0.01).The diagnostic ratios and the positive matrix factorization analysis(PMF)model indicated that the PPAHs in the study area mainly came from petrogenic sources and petroleum residues,biomass combustion,and mixed combustion sources,accounting for 6.60%,32.86%,and 60.54%,respectively.PAH derivatives were mainly from other industrial sources,vehicle emissions,automobile and shipbuilding industries,coal/biomass combustion,and secondary formation,accounting for 7.25%,21.12%,24.55%,25.74%and 21.34%,respectively.The results of the concentration weight trajectory(CWT)model showed that the potential geographic sources of various pollution sources of PPAHs and their derivatives are mainly concentrated in local sources(Shandong Province),followed by neighboring areas such as Hebei and Bohai Sea region.Health risk analysis showed that Benzo[a]pyrene is the major substance in the total carcinogenic equivalent toxicity(∑TEQ)and total mutagenic equivalent toxicity(∑MEQ)of PPAHs and their derivatives,and the mean value of ∑TEQ exceeded the WHO limit value(1 ng/m3)in winter,but not in summer.Incremental lifetime cancer risk(ILCR)model of PPAHs and their derivatives analysis showed that male adults were highest,followed by female adults,female adolescents,male adolescents,female children,and male children.In winter,the ILCRs of all six populations at the urban coastal sampling site exceeded the US EPA acceptable standard(10-6). |
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