污灌区农田土壤多环芳烃污染及风险评价

Contamination and risk assessment of PAHs in agricultural soil from wastewater irrigated area

污灌区农田土壤可能受到多环芳烃(PAHs)的严重污染.本文以山西省黎城污灌区为研究对象,对其中农田土壤中16种优控PAHs的含量水平、组成特征以及风险进行分析和评价.结果表明,该污灌区农田土壤中PAHs总含量范围为16.03—1320.95 ng·g^(-1),平均值为226.74 ng·g^(-1).土壤中PAHs以4—6环的PAHs为主,占总量的61%.风险评价结果显示该区域有40%的样品受到污染,其中重度、中度和轻微污染所占比例分别为2.9%、2.9%和34.3%.健康风险评价结果显示,该区域已具有潜在的致癌风险.从污染评价结果以及与山西省内其它区域农田土壤多环芳烃含量比较来看,研究区土壤已经受到PAHs不同程度的污染.在未来环境管理和控制过程中应采取有效措施,以保护人体健康和生态环境安全.

Agricultural irrigation with wastewater contaminated with polycyclic aromatic hydrocarbons （PAHs） can cause serious soil pollution. A total of 35 soil samples were collected from Licheng wastewater irrigated areas of Shanxi province,and a comprehensive study was conducted to characterize the PAH concentration,composition,as well as the pollution pattern and risk. The results showed that the total concentrations of 16 priority PAHs ranged from 16.03 to 1320.95 ng·g-1,with the average concentration of 226.74 ng·g-1. The PAHs with four to six rings represented more than 61% of the total PAHs. Forty percent of the soil samples were contaminated with PAHs,and 2.9% of the soil samples were in the heavily contaminated category,2.9% of the soil samples were in the moderately contaminated category,and 34.3% of the soil samples were in the slightly contaminated category. The assessment results suggest potential carcinogenic risk of soils to humans,thus some risk control measures should be developed for the safety of the environmental and human health.