拉拉铜矿区土壤重金属含量及其污染特征

HEAVY METAL CONCENTRATIONS OF SOILS IN LALA COPPER MINE AND HEAVY METAL CONTAMINATION

分析了拉拉铜矿区土壤中重金属含量,并运用地积指数对其污染状况进行了评价。结果表明,拉拉矿区是Cu、Cd、Hg污染严重的区域,而Cr、Pb、As污染不明显。与中国土壤元素背景值相比,矿区土壤中Hg含量平均增加了13.4倍,Cd含量平均增加了19.5倍,Cu含量平均增加了4.9倍。运用Muller地积指数进行评价,证明拉拉矿区Cd属于强-极强污染;Hg属于强污染;Cu以中等污染为主,部分强污染;Cr属于无-中污染;Pb以无污染为主;As属于无污染。矿区土壤重金属污染程度由高到低依次为:Cd>Hg>Cu>Cr>Pb>As。建议重视矿区Cu、Cd、Hg等重金属的污染问题,加强重金属的生态健康效应研究。

The concentrations of heavy metals of soils were analyzed and their contaminations were studied in the Lala copper mine. The Lala copper mine is a seriously contaminated region by cadmium, copper and mercury but no contamination by chromium, lead and arsenic. The concentrations of mercury, cadmium and copper in soils in the Lala mine are as 13.4, 19.5 and 4.9 times higher than the average background values of soils in China, respectively. Using the index of geoaccumulation developed by Muller, we found that soils in the Lala mine is seriously polluted by cadmium, heavily polluted by mercury and moderately polluted by copper, while the soils are not or moderately polluted by chromium with no pollution by lead and arsenic. The pollution intensity of soils in the Lala mine follows the order of Cd〉Hg〉Cu〉Cr〉Pb〉As. So not only soil contamination by copper, cadmium and mercury should be emphasized, but also zoological health effect should be taken into consideration.