陕北地区土壤重金属污染特征及生态风险评价

以陕西省靖边县表层土壤(0~20 cm)为研究对象,应用SPSS 19.0软件分析土壤样品中重金属Cr、Cu、Zn、As、Cd、Pb、Hg等7种重金属的含量及来源,运用Hakanson潜在生态危害指数法评价研究区土壤重金属潜在生态危害程度。结果表明,研究区土壤重金属平均含量均低于《土壤环境质量标准》二级标准,各重金属元素变异性较小;相关性分析表明,研究区土壤重金属元素中Cu、Zn、As、Pb两两之间呈极显著的正相关关系;因子分子显示,土壤中重金属的主要来源可能包括研究区附近石油开采活动、交通运输、无机农药和化肥的施用以及工业和居民燃煤等;生态危害评价显示,研究区土壤中仅有Cd元素存在潜在生态风险,其他Cr、Cu、Zn、As、Pb、Hg 6种元素的潜在生态风险均处于低危害水平。

Pollution Characteristics and Potential Ecological Risk Assessment of Soil Metals in the North Area of Shaanxi Province, China

The contents and source of soil heavy metals, such as Cr, Cu, Zn, As, Cd, Pb and Hg in surface soil(0~20 cm)of Jingbian County were analyzed by SPSS 19.0. The soil potential ecological hazards of heavy metals were evaluated using the Hakanson potential ecological risk index. The results showed that the average contents of selected heavy metals were lower than the environmental quality secondary standard values of soils, and variability of most heavy metals were low. The correlation analysis showed that Cu, Zn, As, Pb had good correlations. The factor analysis results suggested that the main source of heavy metals in the soil were the oil exploration activities, transportation, the use of pesticides and fertilizers, industrial and residential coal-fired. The potential ecological risk assessment showed that the risks of Cr, Cu, Zn, As, Pb and Hg were on a low level, except Cd.