Distribution Characteristics and Sources of Polycyclic Aromatic Hydrocarbons in Surface Soil

The concentration and composition of 16 polycyclic aromatic hydrocarbons(PAHs)on the US EPA priority pollutant list in surface soil of Nanchong were determined by gas chromatography(GC).The source of PAHs contamination in surface soil was also diagnosed by using PAH isomer ratios.The results showed that the concentration of PAHs in all soil samples from ten different function area were between 9.1 and 2 269.1 μg·kg-1,and the pollution in industrial area was more serious than that of in agricultural and residential zones.In industrial area,the rule of PAHs content in soil was four-ringtwo-ring three-ring five-ring six-ring,while in agricultural and residential zones it was two-ring three-ring five-ring four-ring six-ring.Compared PAHs contents in soils with other regions reported,the degree of PAHs pollution in the areas was at medium level.Coal and wood and fossil fuels combustion were the dominant sources of PAHs in the areas,and benzo(a)anthracene and phenanthrene were major PAHs pollutants.