Abstract:Levels, carcinogenic risks and sources of sixteen polycyclic aromatic hydrocarbons (PAHs) were analyzed in 227 surface farmland soil samples collected from Huanghuai Plain. The results showed that 15 PAHs (except for acenaphthylene) were generally detected, and the detection ratios ranged from 23.3% to 100%. The total concentrations of 16 PAHs (∑PAH15) varied from33.44 μg/kg to 1246 μg/kg, with a mean value of 152.4 ± 166.2μg/kg, while four and more rings PAHs were the majority dominant components of ∑PAH15. Compared with those in other regions around the world, there was a lower PAHs level in soils of Huanghuai Plain, but 16.7% soil samples exceeded the polluted level (200 μg/kg). According to PAHs toxic equivalent concentration (TEQBap), seven possible carcinogenic PAHs accounted for 98.27% of the total TEQBap, and Benzo (a) pyrene (Bap) had maximum potential carcinogenic risk in farmland soils of Huanghuai Plain. The PAHs isomer pair ratios and principal components analysis indicated that PAHs in Huanghuai Plain farmland soils mainly originated from combustion of gasoline, diesel, coal and straw. A correlation analysis showed that the total concentrations of PAHs and individual PAHs were significantly correlated with soil organic matter, which suggested that soil organic matter was an important factor influencing the distribution of PAHs in soil.