基于GIS矿区土壤重金属生态环境及人体健康评价

结合调整评估阈的潜在生态风险评估和符合我国人体暴露特征参数的人体健康风险评价法,对我国典型多金属矿区—苏仙区的土壤重金属污染进行评价,并利用GIS分析了潜在生态风险等级空间分布,探究了成人及儿童致癌及非致癌健康暴露风险.结果显示,土壤中砷(As)、汞(Hg)、铜(Cu)、铅(Pb)、锌(Zn)5种重金属含量均超出背景值,且单因子污染指数均大于1,综合污染指数达11.6.单因子潜在生态风险评价结果显示,全境内Zn和Cu处于轻微污染及以下;As污染呈西北(中度)—东南(强烈)污染风险走向,中度污染风险等级面积是强烈污染风险等级面积的2倍,空间上看,As的强烈风险区域覆盖柿竹园大型矿区位置;Pb在大型矿区位置周围形成面状3级(重度)污染风险区;整个研究区Hg潜在污染风险处于重度及以上等级.综合潜在生态风险评价结果显示,全境土壤污染主要以重度及强烈等级为主,高风险(强烈等级)区域在空间上覆盖柿竹园大型矿区所在地,并向东南方向面状延伸至研究区边界处.人体健康风险评价显示,针对成年群体,研究区存在显著综合非致癌健康暴露风险,其中,As对非致癌健康暴露风险的贡献最大;对于儿童群体,As、Pb的儿童非致癌健康暴露风险显著,手口摄入是这两种重金属儿童非致癌风险的主要暴露途径;致癌重金属As对成人不存在显著致癌风险,但儿童的致癌健康暴露风险显著.

Assessment of ecological environment and human health of heavy metals in mining area based on GIS

Using the potential ecological risk assessment method with adjusting evaluation threshold and the human health risk assessment method with suitable human exposure parameters, combined with GIS technology, we evaluated the soil heavy metal pollution, analyzed the spatial distribution of potential ecological risk level, and explored the carcinogenic risk and non carcinogenic risk of adults and children in mining area. The result shows that:1the average contents of arsenic(As), mercury(Hg), copper(Cu), lead(Pb) and zinc(Zn) are all exceed the soil background value. The single factor pollution index is greater than 1, and the comprehensive pollution index is as high as 11.6. 2 Single factor potential ecological risk. The potential ecological risk of Zn and Cu are at slight or lower level. As presents the northwest (moderate) -southeast (strong) risk trend, and the area of medium risk is twice as much as strong risk, which is concentrated in the Shizhuyuan mining area. A large area with 3 risk level (heavy) of Pb pollution was close to large mining region. Potential ecological risk of Hg is at or above heavy level in the entire study area. 3 Comprehensive potential ecological risk. Heavy and strong risk levels dominate in the study area. The high risk (strong level) coveres the Shi Zhuyuan large mining area and extends from the southeast to the boundary of the study area. 4 Human health risk. For adults, there is a significant comprehensive non carcinogenic health risk in the study area, and As contributed the most among the five heavy metals. For children, the heavy metals with the greatest risk of non carcinogenic health exposure are As and Pb, and hand-mouth intake is the the main non carcinogenic risk exposure pathways for these two heavy metals. As does not present a significant carcinogenic risk to adults, but the risk of cancer in children is significant.