九龙江流域土壤中多环芳烃分布、来源及风险评价

Distribution,source and risk assessment of polycyclic aromatic hydrocarbons(PAHs)in soils from Jiulong River Basin

2009年3月采集九龙江流域19个表层土壤样品,用GC-MS进行16种优先控制污染物多环芳烃（PAHs）的检测。16种优控PAHs的含量（质量分数）范围为70.70~364.46μg/kg,平均含量为177.03μg/kg,检测率为100%,说明九龙江流域土壤中PAHs的残留普遍存在。和其他地区土壤PAHs含量相比,九龙江流域土壤PAHs污染处于较低水平。通过PAHs组分比值和因子分析等方法,得出土壤PAHs污染来源于石油的燃烧。根据荷兰农业土壤标准,采用毒性当量因子分析得出10种PAHs的毒性当量浓度（TEQBaP）为0.63~17.28μg/kg,小于参考值33μg/kg,说明九龙江流域土壤不存在潜在风险,同时发现,7种致癌物质的TEQBaP占16种PAHsTEQBaP的81%~98%,是其主要贡献者。

Nineteen surface soil samples were collected in March 2009from Jiulong River Basin and 16kinds of priority control pollutants,i.e.,polycyclic aromatic hydrocarbons（PAHs）,were detected by GC-MS.The total mass fraction of PAHs in the soils ranged from 70.70to 364.46μg/kg,with a mean value of 177.03μg/kg.Each of the 16PAHs was detected in all soil samples.The mass fraction of PAHs in the study area was at a low level compared with that of other regions.The isomeric ratios and factor analysis revealed that the PAHs in Jiulong River Basin were contributed mainly by petroleum combustion.According to the Dutch agricultural soil standard,the toxic benzo[a]pyrene equivalents（TEQBaP）of the 16 PAHs varied from 0.63to17.28μg/kg,which is lower than the reference value（33μg/kg）,suggesting that all soils in Jiulong River Basin may have no potential ecological risk.But 81%~98%of TEQBaP of the 16PAHs was contributed by seven carcinogenic PAHs,which were the major contributors.