贵州马岭工业区土壤重金属污染现状及生态风险评价

Pollution status and potential ecological risk assessment of soil heavy metals in Maling industrial area in Guizhou Province

[目的]了解贵州马岭工业区土壤中重金属污染状况,为制定该工业区重金属污染研究和防治对策提供科学依据。[方法]以马岭工业区南北向约4 km、东西向2.5 km的10 km2区域为研究区,通过等距网格布点,采集表层土壤样品共计30个,采用污染指数法和潜在生态风险指数法,对工业区的土壤重金属铜(Cu)、锌(Zn)、铅(Pb)、镉(Cd)、砷(As)和汞(Hg)的污染状况及潜在生态风险进行评价。[结果]马岭工业区土壤Cu、Zn、Pb、Cd、As和Hg的单项污染指数分别为0.63、0.86、0.84、1.43、0.62、2.23;土壤综合污染指数在0.27~5.83间,均值为1.73,为轻度污染。土壤重金属元素的潜在生态危害性为Hg>Cd>As>Pb>Cu>Zn,其中Hg和Cd是主要的生态风险贡献因子。[结论]土壤总体处于轻度污染状态,但Hg已达到较严重的生态危害程度,应引起足够重视。

[ Objective ] To evaluate soil heavy metal pollution levels in Maling industrial area in Guizhou, and to provide scientific evidence for making corresponding prevention and control strategies. [ Methods ] By equidistant grid arrangement of sampling points, 30 surface soil samples were collected in a 10-km2 area stretching about 4 km in north-south direction and 2.5 km in east-west direction in Maling industrial area. The pollution indices and potential ecological risk indices of copper （Cu）, zinc （Zn）, lead （Pb）, cadmium （Cd）, arsenic （As）, and mercury （Hg） were calculated. [ Results ] The single pollutant indices of Cu, Zn, Pb, Cd, As, and Hg in the soil samples collected in Maling industrial area were 0.63, 0.86, 0.84, 1.43, 0.62, and 2.23, respectively. The soil comprehensive pollution indices ranged from 0.27 to 5.83, with an average of 1.73, which indicated lightly polluted soil. The heavy metals with their potential ecological risks from high to low were Hg〉 Cd 〉 As 〉 Pb 〉 Cu 〉 Zn, and Hg and Cd were the main contribution factors to the ecological risk. [ Conclusion ] The soil is lightly polluted in general. However, a severe ecological risk of Fig is identified, which should be paid enough attention to.