我国南方某典型有机化工污染场地土壤与地下水健康风险评估

摘要

Tiered human health risk assessment of soil and groundwater were undertaken for a typical organic chemical contaminated site in southern China.The screening levels and remediation targets of chemicals of concern (COCs) in soil and groundwater,as well as the corresponding remediation area were calculated.The results indicated that both soil and groundwater were contaminated by organic compounds with different levels.The derived remediation targets of chloroform,carbon tetrachloride,benzene,chlorobenzene were 0.03,0.05,0.35,6.51 mg/kg in the 0-1 m soil layer; 0.07,0.30,0.90,13.49 mg/kg in the 1-3 m soil layer; 0.14,0.46,1.69,20.45 mg/kg in the 3-5 m soil layer; 0.25,0.79,2.99,36.27 mg/kg in the 5-9 m soil layer,and 0.32,0.51,3.43,21.80 mg/L in the groundwater,respectively.The soil contaminated points of chloroform,carbon tetrachloride and chlorobenzene,as well as their corresponding cancer risk or hazard index values were increased with the increase of soil depth.The contaminated area of groundwater were gathered together.The concentrations of four COCs in groundwater (GW6) were beyond their remediation targets,and chloroform was the most serious contaminant with cancer risk and hazard index of 1.11 × 10-3 and 9.8,respectively.%以某典型有机化工污染场地为例,开展了多层次健康风险评估,推算了土壤与地下水的筛选值和修复目标值,确定了污染修复范围及修复量.结果表明:土壤与地下水均存在不同程度的有机污染,关注污染物氯仿、四氯化碳、苯、氯苯在0～1m的土壤修复目标值分别为0.03、0.05、0.35、6.51 mg/kg;1～3 m的土壤修复目标值分别为0.07、0.30、0.90、13.49 mg/kg;3～5 m的土壤修复目标值分别0.14、0.46、1.69、20.45 mg/kg;5～9 m的土壤修复目标值分别为0.25、0.79、2.99、36.27 mg/kg,地下水修复目标值分别为0.32、0.51、3.43、21.80 mg/L.土壤中氯仿、四氯化碳、氯苯的超标点位随深度增加而增多,其风险或危害随之增大;地下水污染区域集中,GW6号点位4种污染物均超标,其中氯仿污染最严重,致癌风险高达1.11×10-3,非致癌危害商为9.8.