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

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 PAHs in the aerosols of different function regions of Nanjing City ranged from 19.73 to 497.40 ng/m³; 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, 10 ng/m³), and that of small particles in residential region was higher slightly than the regional standard (BaP, 5 ng/m³); while the PAHs of each function region in winter were basically in serious excess of standard.