107国道新乡某段土壤重金属的多受体暴露风险评价

Spatial Environmental Exposure Risk Assessment of Roadside Soil from 107th National Highway for Multi-receptors

为定量研究交通源重金属污染给公路附近人群健康带来的潜在风险,基于美国环保署(US EPA)"四步评价法",对107国道新乡某段两侧的土壤重金属污染进行了多受体暴露风险评价.结果表明:国道新乡某段两侧的土壤重金属含量随距路基距离的增大基本呈现先增大再减小,而后趋于相对稳定的趋势,但距路基的东、西两侧污染分布特征不尽相同;研究区域重金属总非致癌风险值(HI)均<1,排序为HICd>HICu>HINi,对受体暂时不会造成非致癌健康危害,但儿童作为敏感受体,其HICd接近于1,应引起有关部门重视;重金属总致癌风险对于两类目标受体而言都超过了可接受致癌风险限值1×10-5,R蔬菜经口暴露途径>R误食土壤暴露途径>R皮肤直接接触途径>R土壤颗粒呼吸摄入暴露途径,总风险的主要贡献因子为RCd,主要致癌风险暴露途径为蔬菜经口暴露途径和误食土壤暴露途径,并且路基西侧的污染风险更为严重.

In order to quantitative assessment of heavy metals pollution around roadside soil from 107th national high- way, spatial environmental exposure risk assessment model for multi-receptors was developed based on ＂4 assessment proce- dures＂ designed by US EPA. The results showed the concentrations of different samples decreased gradually with the increas- ing distance from the roadbed. And there were different distribution characters between samples from east side and west side to the road. HI of the study area were all below the accepted risk limit （1）, and in the decreasing order of Hlcd^Hlcu^HIN~. For the children receptor group, Hlcdwas approaching the accepted risk limit （1）, therefore it should be taken attention by the related departments. Carcinogenic risk values of studied soil samples all exceed the corresponding accepted risk limit 1 ×10^-1, and in order of R1〉Rs〉Ra〉Rb. And the risk of soil heavy metal from west side to roadbed was bigger than that from the east side.