工业城市不同功能区土壤和蔬菜中重金属污染及其健康风险评价

为了研究和评价工业城市不同功能区的土壤和蔬菜中重金属污染和健康风险状况,以株洲市为例,在工业区（石峰区）、农业区（芦淞区）和旅游区（大京风景区）分别采集土壤和蔬菜样品,分析重金属Cd、As、Pb、Hg、Zn、Cr和Cu的质量分数,并采用地质累积指数法（Igeo）和健康风险评价模型分别对土壤和蔬菜中重金属进行评价。结果表明：工业区、农业区和旅游区土壤中Cd、As、Pb、Hg、Zn、Cr和Cu的平均质量分数都超出湖南省土壤背景值,部分重金属甚至超出国家土壤环境质量二级标准。不同功能区土壤中重金属的地质累积指数（Igeo）表明：工业区、农业区和旅游区土壤受到不同程度的重金属污染,其中Cd和Hg的污染最为严重,污染程度依次是工业区〉农业区〉旅游区。不同功能区蔬菜中Cd、As、Pb和Zn的危害商（HQ）值都大于1.0,而Cu和Cr的危害商（HQ）都小于1.0。不同功能区蔬菜中重金属危害指数（HI）都大于10.0,尤其是工业区蔬菜的危害指数（HI）〉100.0,当地成年人食用受到重金属污染的蔬菜会导致严重的健康危害,其中Cd和As,是危害指数（HI）的主要贡献者,两者贡献率之和的范围为75%~89%,而Cr的贡献率几乎为0。

The pollution and health risk assessment of heavy metals in soils and vegetables from different function areas in industrial city

To assess the pollution and human health risks induced by heavy metals in industry city,the total concentrations of Cd,As,Pb,Hg,Zn,Cr and Cu in soils and vegetables from industrial district（Shifeng district）,agricultural area（Lusong district）and the landscape area（Dajing scenic district）in Zhu Zhou city of Hunan province were analyzed.The results indicated that the concen-trations of Cd,As,Pb,Hg,Zn,Cr and Cu in all soils were significantly higher than those of the background values from other part of Hunan Province,and some of heavy metal contents even exceeded the values of National Standards（Grade 2）for Soil Environmental Quality of Heavy metals by the State Environment Protection Administration of China（SEPA）.The geoaccumulation index（I-geo）of heavy metals showed that those soils form different function areas suffered from the pollution,and Cd and Hg were the predominant pollutants in all soils.The most serious pollution occurred in industrial area,followed agricultural area and landscape area.The re-sults of hazard quotient（HQ）and hazard index（HI）for an adult through consumption of vegetables indicated that the HI values of all heavy metals in the different function areas were higher than 10.0,specially in industrial areas was higher than 100.00,suggesting that consumption of contaminated vegetables would lead to the high chronic risk for an adult.Among all heavy metals investigated,Cd and As were the major contributors for an adult through vegetables consumption amounting for 75% to 89% of HI,while Cr was a minimal risk contributor.