DISTRIBUTION,SOURCE IDENTIFICATION AND RISK ASSESSMENTOF POLYCYCLIC AROMATIC HYDROCARBONS IN ARABLE SOILS ATATYPICAL LONGTERM COKING PRODUCTION BASE IN NORTH CHINA

摘要

Coking is a main industrial emission source ofpolycyclic aromatic hydrocarbons (PAHs) in China.Acomprehensive studywas conducted of theconcentrations,spatial distribution,sources,and thepotential human health risks of 16 priority PAHs inag ricultural soil within 2000 m of a Coking Plant inShanxi,North China,which has been in productionfor more than 20 years.Diagnostic ratios wereemployed to identify the sources of PAHs.Tox icequivalency factors of benzo[a]pyrene were used toevaluate the health-risk of PAHs.Results showedthat the total concentrations of the 16 PAHs rangedfrom 2297to 9421ng/g.The mean totalconcentrations of15relativelystable PAHs(15PAHs) in agricultural soil around the cokingplant were 6591,4518and 2208 ng/g at thedistances of 1000,1000~1500 and 1500~2000 m,respectively.> 15PAHsdecreased with theincreasing distance from the emission source.The4-5-rings PAHs offluoranthene,pyrene,benz[aJanthracene and chrysene were the mostdominant components with an average percentagecontribution of 52.72%.The PAHs in soils weremainly from pyrogenic sources,especially coalcombustion.The benzo[a]pyrene concentrations of7carcinogenic PAHs accounted for 83% of the total15 PAHs.The >PAHszc mainly contributed to thepotential carcinogenic risk for humans,whichdeclined with distances increasing in 2000m.Long-term exposure to coking plants potentiallyinduce human health risks.