中文摘要：

为揭示我国重要化工城市郊区蔬菜土壤中多氯联苯(PCBs)的残留现状,对吉林市城郊菜田表层土壤中11种多氯联苯的含量及分布特征进行了分析,并采用环境质量标准风险评价法和毒性当量因子法进行了生态风险评价。结果表明:研究区蔬菜土壤中多氯联苯总量的空间变异较大,变化范围为58.20~253.08μg·kg-1,平均含量达111.00μg·kg-1,部分超出土壤环境质量二级标准,已存在一定的潜在危害;土壤中多氯联苯同系物以五氯及以上的高氯联苯为主,占总量的63.27%;多氯联苯含量最高值主要分布在城郊北部,即吉林市化工厂集中区,表明该区域蔬菜土壤环境质量受人为活动影响较显著。主成分分析发现:主成分1的方差贡献率为31.67%,主要来自油漆、绝缘材料等工业品;主成分2的方差贡献率为20.05%,主要来源于电力电容器的浸渍剂;主成分3和主成分4的方差贡献率分别为11.16%和9.62%,主要来源于废弃物焚烧及增塑剂中PCBs的挥发。总体上看,吉林市近郊蔬菜土壤中多氯联苯污染水平或毒性当量处于中度生态污染水平,已具有一定的潜在生态风险,应引起足够重视以避免对人体健康构成威胁。

英文摘要：

Polychlorinated biphenyls(PCBs)have contaminated agricultural soils. In order to investigate residues and ecological risks of polychlorinated biphenyls(PCBs)in vegetable soils in Jilin suburbs, we analyzed concentrations and distribution characteristics of 11 PCBs in the vegetable topsoils from Jilin suburbs, assessed the ecological risks using environmental quality standard and toxicity equivalent factor. The total concentrations of PCBs in the vegetable soils varied greatly, ranging from 58.20 μg·kg-1 to 253.08μg·kg-1, with an average con-centration of 111.00μg·kg-1. The total concentrations of PCBs in some areas exceeded the secondary standard of the national soil environ-mental quality, indicating potential risks in the vegetable fields. Soil PCBs were mainly five- or more ring congeners. The highest concentra-tion of PCBs was found in the northern suburbs, where chemical plants were highly concentrated, showing the impact of human activities on the environmental quality of vegetable soils in this area. Principal component analysis revealed that the principal component 1 contributed 31.67%to the variance, mainly from paint, insulation materials and other industrial products. The principal component 2 made 20.05%con-tribution to the variance, which resulted from power capacitor impregnant. The percent contribution of principal component 3 and 4 were re-spectively 11.16%and 9.62%, which were waste incineration and volatilization of PCBs in plasticizer. Overall, the pollution level or toxic e-quivalence of PCBs in vegetable soils of Jilin suburbs was at a moderate level, and posed a potential ecological risk. Attentions should be paid to their threats to human health.