程潮矿区周边土壤重金属污染风险评价和健康风险评估

采用单因子指数法、内梅罗指数法、潜在生态风险指数法和地累积指数法对程潮铁矿尾矿库及周边农田土壤重金属（镉、砷、铅、铬、铜、镍和锌）的生态风险及人体健康风险进行综合评价。单因子风险评价结果显示，尾矿库土壤As和Cu的污染问题突出，超标率分别为33.3%和41.7%，其它重金属在少数点位超标；农田土壤仅重金属Cd超标。内梅罗综合污染指数结果表明，16.7%的尾矿位点处于中度污染水平，25%的尾矿位点处于重度污染水平；农田土壤整体上较清洁。尾矿土壤中41.7%的Cu处于中等潜在生态风险水平，41.7%的土壤Cu属于中度~强污染地质累积风险，少数位点由于Cd和As含量较高，达到较高等级的潜在生态风险和地质累积风险。农田土壤重金属污染物主要为Cd，局部地区达到中等潜在生态风险和地质累积风险。人体健康风险评价结果表明，As和Cr的非致癌风险和致癌风险均较为突出，整体而言，尾矿区有33.3%的位点存在致癌风险，所有土壤的非致癌风险等级低，对人体健康的风险较低。由于少数位点重金属污染问题突出，仍需加强该尾矿及其周边农田土壤重金属的污染防治和风险管控。

Risk Assessment and Health Risk Assessment of Soil Heavy Metal Pollution in Chengchao Mining Area

Ecological risks, as well as the human health risks, of heavy metals (cadmium, arsenic, lead, chromium, copper, nickel and zinc) in tailings pond of Chengchao Iron Mine and the surrounding farmland soil were comprehensively evaluated by single factor index, Nemero index, potential ecological risk index and ground accumulation index. The results of single factor risk assessment show that the pollution of As and Cu in tailings pond soil is prominent, and the overstandard rates are 33.3% and 41.7%, respectively. Other heavy metals exceeded the standard at a few points. Only heavy metal Cd exceeds the standard in farmland soil around the mining area. Nemero comprehensive pollution index results show that 16.7% of tailings sites are at moderate pollution level, and 25% of tailings sites are at severe pollution level. Farmland soil is generally cleaner. In tailings soil, 41.7% Cu is at the medium level of potential ecological risk, and 41.7% Cu belongs to the geological accumulation risk of moderate to strong pollution. A few sites have higher levels of potential ecological risk and geological accumulation risk due to the high content of Cd and As. The main heavy metal pollutant in farmland soil is Cd, and the potential ecological risk and geological accumulation risk are moderate in some areas. The results of human health risk assessment show that the non-carcinogenic risk and carcinogenic risk of As and Cr are prominent. Overall, 33.3% of the sites in the tailing area have carcinogenic risk, and all the soil has low non-carcinogenic risk and low risk to human health. Due to the serious heavy metal pollution problems at a few sites, it is still necessary to strengthen the pollution prevention and risk control of heavy metal pollution in the tailings and surrounding farmland soil.