西华山钨矿区菜地土壤重金属污染特征评价与健康风险评估

研究赣南西华山钨矿开采对周边菜地土壤和蔬菜的影响,采集矿区17个蔬菜地土样和十个品种蔬菜样,运用SPSS软件分析土壤及蔬菜中重金属含量分布特征,以江西省土壤背景值为参照,采用单项污染指数法、内梅罗综合污染指数法、Muller地累积指数法、Hankanson生态危害指数法和健康风险评估模型分别对土壤进行重金属污染评价、潜在生态风险评估、蔬菜食用安全性评估。结果表明,钨矿区菜地土壤受到严重的重金属污染,其中镉污染最为严重,9号点位高达21.5 mg/kg。17个点位中有16个为重度污染,评估表明研究区具有较强的潜在生态风险,镉为研究区生态风险主要贡献者。蔬菜中镉污染最为严重,饮食摄入风险评估表明,镉致癌风险指数为1.403;对铬、铜、铅、锌四种元素的非致癌风险评估表明:铬非致癌风险指数高达206.01,远远超出美国环保署作出的健康限值,居民通过蔬菜途径摄入的铬和镉对人体健康均存在较大的健康风险。

Evaluation of Heavy Metal Pollution and Health Risk Assessment in Xihuashan Tungsten Mine

In order to study the impact of mining exploitation on vegetable soil and vegetables surrounding the Xihuashan Tungsten Mine, 17 samples of vegetable soil and 10 samples of vegetables were collected. SPSS and ArcGIS software were used to analyze the distribution characteristics of heavy metals in soil and vegetables. Using the soil background values in jiangxi province as the reference, the Single Pollution Index, NemerowSIntegratedSIndex, Muller Cumulative Index and Hankanson Ecological Damage Index methods, health risk assessment model were introduced to evaluate heavy metal pollution of soil, potential ecological risk assessment and vegetable edible safety assessment. The results show that severely heavy metals pollution on vegetable field around Tungsten Mine, in which Cd pollution was most serious and 21.5 mg.kg-1 at No.9. The 16 points from 17 are severe pollution and has critically potential ecological risk. Element Cd is the major contributor for the ecological risk in the study area. Cd pollution in vegetables is most serious, in which the highest was 58 mg.kg-1 in Shanghai branch. Diet risk assessment shows that the carcinogenic risk index of Cd in vegetables was 1.403, non-carcinogenic risk index of Cr 206.01, which largely beyond the limit of health to the EPA. The health risk of Cr, Cd is very high from vegetable intake for residents.