Analysis On Characteristics And Sources Of PM-bound PAHs,NPAHs And OPAHs In Urban Area And Background Site

In order to study the pollution characteristics of PAHs,NPAHs and OPAHs in the background site and urban area,the PM2.5 and PM1.0 in Mont Tai,and the PM2.5 in Jinan was collected,and the 18 PAHs、14 NPAHs and 5 OPAHs were analyzed by GC-MS in this study.The pollution characteristics of PAHs,NPAHs and OPAHs under different weather conditions in PM2.5 and PM1.0 in the background site,and the concentrations,composition distribution diversity,sources and ancer risk assessment of PAHs,NPAHs and OPAHs in urban in summer and winter were discussed in this paper.Based on the analysis experimental data,this study has obtained the concentration characteristics of PAHs,NPAHs and OPAHs in background and urban sampling sites.In background site.The concentrations of PAHs and NPAHs were highest in biomass burning stages,and the minimum concentrations appeared on the clean days.In addition,NPAHs and OPAHs were mainly distributed in PM1.0.The PAHs,NPAHs and OPAHs in PM2.5 in Jinan were higher in winter than that in summer.Compared with the clean days,the proportion of LMW-PAHs and MMW-PAHs decreased,and the proportion of HMW-PAHs increased at polluted days in PM2.5 in Mount Tai.Compared with clean and polluted days,the proportion of LMW-PAHs decreased,and the proportion of MMW-PAHs and HMW-PAHs in PM2.5 increased during biomass burning in Mount Tai.PAHs in PM2.5 in urban of Jinan were dominated by MMW-PAHs and HMW-PAHs.In addition,2+3N-FLA and 9N-ANT significantly increased during biomass burning.There are differences in the composition of NPAHs in summer and winter in urban of Jinan.The composition of OPAHs in background and urban sites din’t show obvious differences in different seasons and weather conditions.The sources of PAHs in the background site mainly include fossil fuel and biomass burning;the NPAHs were mainly from the secondary generation during pollution and biomass burning days,and the secondary generation is more active during biomass burning.PAHs in urban areas of Jinan were affected by biomass burning and coal combustion respectively in summer and winter.In addition,vehicle exhaust emissions were also the main sources of PAHs in urban areas of Jinan.In summer,NPAHs were mainly from direct emissions,while,NPAHs were mainly from secondary generation in winter.This study analyzed the effects of long-range air transmission on PAHs,NPAHs and OPAHs concentrations in background site using HYSPLIT model.The results showed that,the concentrations of PAHs,NPAHs and OPAHs are affected by local source,long-range transport,and biomass burning.The life cycle-increased cancer risk(ILCR)was used to assess the cancer risk of PAHs and NPAHs,the risk assessment results showed that,the cancer risk of PAHs and NPAHs was highest in biomass burning stage in background site.In urban site,the higher the number of ring PAHs,the greater harm to human.Compared with the PAHs,the toxic effects of NPAHs were much stronger than PAHs.In addition,the risk of cancer increased with the increase of exposure time.