基于GIS的县域土壤重金属健康风险评价——以浙江省慈溪市为例

以浙江省慈溪市为例,基于GIS平台,对农业土壤中重金属的污染状况分别进行单因子健康风险评价和健康总风险评价。单因子健康风险评价结果显示,慈溪市表层土壤重金属As的致癌风险指数在10-6～10-5水平,部分地区的风险指数已经超出美国EPA的土壤治理基准(10-6),Cd的致癌风险指数在10-7水平,属于安全的范围。七种重金属的非致癌风险指数均远小于限值1,不会对当地居民身体健康产生太大危害。健康总风险评价结果显示,叠加后的致癌总风险值指数仍处于10-6水平,叠加后的非致癌总风险指数值在10-2～10-1水平,也不会对当地居民的身体健康产生较大危害。但在今后的土地利用规划中,仍要加强土壤重金属的健康风险防范。

Health Risk Assessment on Heavy Metals in Soil Based on GIS——A Case Study in Cixi City of Zejiang Province

GIS was applied to analyze the pollution of heavy metals in Agricultural Soils in Cixi conty,Zejiang province,and the health risk assessment was also performed based on the single factor and integrate factors.The results of single factor assessment showed that the cancerous risk indexes of As in Cixi surface soil is in the range of 10-6-10-5 and some of areas the indexes has exceeded the soil management standard value of EPA;the cancerous risk indexes of Cd is at the level of 10-7 and it belongs to the safety extension.The non-cancerous risk indexes of seven heavy metals is also less than the limit value 1 and will not harm the local people.The results of the integrate factors health risk assessment showed that the total cancerous risk indexes are still at the level of 10-6,the total non-cancerous risk indexes are in the range of 10-2-10-1,and will not harm the local people either.