福建闽江沿岸土壤中多环芳烃含量、来源及健康风险评价

为研究福建省闽江沿岸土壤中多环芳烃(PAHs)的残留状况、潜在来源及健康风险,采集闽江沿岸16个土壤样品,利用气相色谱/质谱(GC/MS)分析其中16种PAHs含量,结果表明:研究区土壤中16种PAHs的总含量为70.70~1667.83μg/kg,平均值为480.28μg/kg,其沿闽江沿岸呈“W”型分布模式,具体表现为城市高于郊区的变化;PAHs以2~3环为主,其中萘(Nap)的含量最高.基于PAHs的特征比值和主成分回归结合分析,研究区土壤中PAHs主要是石化和燃烧混合污染源,其中化石燃料高温燃烧占41.45%,石油源及生物质燃烧占49.34%,煤燃烧占9.21%.PAHs总毒性当量浓度值(TEQ_BaP)为3.10~121.15μg/kg,平均值为36.71μg/kg,37.50%的采样点超过荷兰土壤标准目标参考值(33.00μg/kg),表明闽江沿岸土壤已经受到PAHs不同程度的污染.健康风险评价表明,研究区土壤中PAHs的致癌风险(ILCRs)在10^-8~10^-6间,说明其致癌风险较小.

Concentrations,sources and health risk assessment of polycyclic aromatic hydrocarbons in soils collected along the banks of Minjiang River,Fujian, China

The potential sources and health risks associated with 16 polycyclic aromatic hydrocarbons (PAHs) in 16 samples of topsoil collected from the banks of Minjiang river in Fujian Province, China, analyzed by gas chromatography-mass spectrometry (GC-MS) are discussed. The results indicate the total concentrations of the 16PAHs ranged from 70.70 to 1667.83 μg/kg, with the mean of 480.28 μg/kg. The distribution of the PAHs along the Minjiang River revealed a W-shaped pattern, with the higher concentrations of PAHs detected in the soil of urban districts, and lower concentrations detected in the suburbs. The dominant compounds were 2~3 ring PAHs, with the highest concentrations relating to naphthalene. Diagnostic ratios including the proportions of PAHs, their principle components and multiple linear regression analyses indicate that the sources of the PAHs in soils were most likely a mixture of fossil fuels and combustion residues, namely 41.45% from the combustion of petroleum fuel, 49.34% from the combustion of biomass and petroleum sources, and 9.21% from the combustion of coal. The concentration of the toxic benzo[a]pyrene equivalent (TEQ_BaP) varied from 3.10 to 121.15 μg/kg (mean, 36.71 μg/kg), and in total, 37.50% of the sample sites exceeded Dutch agricultural soil standards(33.00 μg/kg), suggesting the soil is polluted by PAHs. The incremental lifetime cancer risk values (ILCRs) fluctuated from 10^-8 to 10^-6, indicating a lower carcinogenic risk to residents.