Distribution and source apportionment of polycyclic aromatic hydrocarbons in surface soils in Shanghai

The concentrations of sixteen priority polycyclic aromatic hydrocarbons in 80 topsoil samples in Shanghai were determined by GC-MS. The distribution pattern was discussed, and source apportionment of PAHs in surface soil was conducted by the isomer ratio and principal component analysis. Results showed that the concentrations of PAHs ranged between 0.12 μg/g and 24.5 μg/g, presenting gradient changes of suburb>urban> rural and traffic area>cultural and educational area>park greenbelt>business district>residential in different functional areas in the city. Dominant compounds were 4 rings and 5 rings PAHs, which accounted for 49.2% and 27.0%, followed by 3 and 6 rings, which accounted for 14.8% and 6.6% of the total PAH concentrations, respectively. The lowest was the 2 rings PAHs, which only accounted for 2.4% of the total PAH concentrations. In addition, fluoranthene, pyrene and benzopyrene were dominant PAH compounds. Source apportionment indicated that the PAHs originated mainly from burning, mainly oil burning.