锑矿区土壤和蔬菜重金属污染及健康风险评价

Soil-vegetable Pollution of Heavy Metals and Health Risk Assessment in Antimony Mining Area

为探究矿业开采对土壤-作物系统产生的影响,以湖南锑矿区为例,通过野外调查采集土壤、蔬菜和植物样品共233件,分析了矿区土壤和蔬菜中Ni、Cu、Pb、Zn、Cr、Cd、As、Sb、Hg的含量分布,并采用目标危险系数法评价了矿区居民通过食用蔬菜摄入重金属的健康风险。结果表明:表层土壤中Ni、Cu、Pb、Zn、Cr、Cd、As、Sb、Hg平均含量均超过湖南省背景值,Cd和As的平均浓度均超过我国农田土壤风险筛选值。蔬菜中重金属Pb、Cr、Cd、As、Hg五种元素的超标率分别为100%、91.26%、83.50%、80.58%、81.55%,叶菜类对9种重金属的富集能力基本强于其他类蔬菜。矿区成人长期食用白菜会对健康造成影响,且成人摄食蔬菜的重金属健康风险高于儿童。醉蝶花对重金属As和Sb有较强的吸收能力,可作为锑矿区生态恢复中的优势物种。

In order to explore the impact of mining on the soil-crop system,taking the Hunan antimony mining area as an example,a total of 233 soil,vegetable and plant samples were collected through field investigations,and the content distribution of Ni,Cu,Pb,Zn,Cr,Cd,As,Sb,and Hg in soil and vegetables in the mining area were analyzed,and the target risk coefficient method was used to evaluate the health risks of heavy metals ingestion by residents in mining areas through the consumption of vegetables.The results show that the average contents of Ni,Cu,Pb,Zn,Cr,Cd,As,Sb,and Hg are all above the background values of the surface soil in Hunan Province,and the mean concentrations of Cd and As have exceeded China's soil pollution risk screening values for agricultural land.The over-standard rates of the five heavy metals Pb,Cr,Cd,As and Hg in vegetables are 100%,91.26%,83.50%,80.58%,and 81.55%respectively.Among the analyzed vegetables,leafy vegetables had the strongest capacity to accumulate 9 heavy metals.Long-term consumption of cabbage by adults in mining areas would adversely affect health.The health risks posed by the intake of heavy metals in food were higher for adults than for children.Cleome has a strong ability to absorb heavy metals As and Sb,and can be used as a dominant species in the ecological restoration of antimony mining areas.