湘西多金属矿区汞铅污染土壤的环境质量

以湘西典型多金属矿区为现场,研究了矿区土壤中汞、铅等重金属污染状况及成因.结果表明,湘西矿区是汞、铅污染严重的区域,与中国土壤元素背景值相比,汞矿区土壤中汞、铅含量分别增加1315倍和3.1倍,铅锌矿区土壤中汞、铅含量分别增加14.8倍和16.1倍.运用Muller地积指数进行风险评价,证实湘西矿区是汞、铅等重金属的复合污染区,汞矿区汞污染以极重污染为主,铅污染以中度和轻污染为主;铅锌矿区铅污染以中度和中-重污染为主,汞污染以中-重污染为主.矿区土壤中的重金属污染物来源和分布受原生地球化学条件的控制,而人为采矿活动对矿区土壤中汞、铅的污染格局产生重要影响.

Environmental Quality of Soil Polluted by Mercury and Lead in Polymetallic Deposit Areas of Western Hunan Province

The environmental quality of soil polluted by mercury and lead in typical polymetallic deposit areas of western Hunan province and its natural and human causes were studied. It was found that western Hunan province is a high regional geochemical abnormal region on mercury and lead. The concentrations of mercury and lead in soils in mercury deposit areas were (1 315) and 3.1 times higher than that of the average background of soils in China respectively, while those in soils in lead-zinc deposit areas were 14.8 and 16.1 times higher. Using geoaccumulation index developed by Muller, it was found that either mercury deposit area or lead-zinc deposit area in western Hunan province is polluted by the two elements, the majority soils in mercury deposit areas are seriously polluted by mercury with middle polluted or light polluted by lead, while the majority soils in lead-zinc deposit areas are middle polluted or middle-heavily polluted by lead and middle-heavily polluted by mercury. The sources of metal pollutants in soils in the deposit areas are natural and human causal, the spatial distribution of mercury and lead are dominated by original geochemical situation but seriously affected by human mining activities.