南京大气气溶胶中多环芳烃源识别及污染评价

Source identification and pollution evaluation of polycyclic aromatic hydrocarbons in atmospheric aerosols in Nanjing City

采用GC、GC-MS等方法,研究了南京市不同功能区夏、冬季大气气溶胶中多环芳烃(PAHs)的污染状况和污染来源,并对不同功能区的PAHs进行了污染评价.结果表明,南京市各功能区气溶胶中PAHs总量在19.73～497.40ng/m3之间,且冬季高于夏季,细颗粒中含量高于粗颗粒.通过一些特征标志PAHs的比值,可判断夏季各功能区的PAHs污染主要来自于汽车尾气(主要是柴油型)的排放,冬季则为汽车尾气和燃煤污染.采用苯并(a)芘(BaP)及苯并(a)芘等效致癌浓度(BaPE)来评价5个功能区气溶胶中PAHs的污染状况,夏季除交通干道超过国家标准(BaP,10ng/m3),居民区细颗粒中略超过居民区标准(BaP,5ng/m3)外,空气质量良好.而冬季各功能区PAHs基本上均严重超标.

The pollution state and source of polycyclic aromatic hydrocarbons （PAHs） in atmospheric aerosols were studied using GC and GC-MS in different function regions in Nanjing City in summer and winter; and the pollution evaluation of PAHs in different function regions was made. The total amount of PAils in the aerosols of different function regions of Nanjing City ranged from 19.73 to 497.40ng/m^3; and was higher in winter than in summer, with the content of small particles higher than that of large particles. Through some diagnostic index PAHs ratios, the PAHs pollution of each function region in summer might be judged coming mainly from automobile emission （mainly diesel oil）; while in winter from automobile emission and coal burning pollution. Adopting benzo（a） pyrene （BaP） and benzo（a） pyrene-equivalent carcinogenic concentration （BaPE） to evaluate the PAHs pollution state in the aerosols of 5 function regions. The air quality was good in summer except that of the main highway was higher than the national air quality standard （BaP, 10ng/m^3）, and that of small particles in residential region was higher slightly than the regional standard （BaP, 5ng/m^3）; while the PAHs of each function region in winter were basically in serious excess of standard.