秀山县农业区域土壤重金属分布特征及生态风险研究

Study on the Distribution Characteristics and Ecological Risk of Heavy Metals in Agricultural Soils of Xiushan County

[目的]研究秀山县农业区域土壤重金属分布特征及生态风险。[方法]以秀山县农业区域土壤为研究对象,采用单项污染指数法、内梅罗综合污染指数法、地质积累指数法和潜在生态危害指数法对土壤中重金属进行特征分析及生态风险评价。[结果]研究区域土壤中As、Cd、Cr、Hg、Pb 5种重金属的平均含量均符合《土壤环境质量标准》(GB 15618—1995)二级标准要求,除Cr外,其余4种均高于重庆市土壤背景值。土壤中重金属元素的污染程度从大到小依次为As、Cd、Hg、Cr、Pb,平均单项生态风险因子由强到弱依次为Hg、Cd、As、Pb、Cr,其中Hg处于很强生态风险,另外4种重金属均处于较低生态风险水平。[结论]该研究可为秀山县生态环境保护提供科学参考。

[Objective]To study the distribution characteristics and ecological risk of heavy metals in agricultural soils of Xiushan County.[Method]Taking the agricultural soil in Xiushan County as the research object,the characteristics of heavy metals in the soil and ecological risk assessment were carried by the single factor pollution index method,nemero comprehensive pollution index method,geological accumulation index method and potential ecological hazard index method. [Result]The results showed that the average content of As,Cd,Cr,Hg,Pb were in accordance with the soil environment quality standard the secondary standard（ GB15618—1995） in research area soil heavy metals. In addition,the average content of Cr was lower than the soil background values in Chongqing,the rest of the four kinds of heavy metal was higher than its background values. The pollution degree of heavy metals in soil ranged from big to small were As,Cd,Hg,Cr,Pb,the average individual ecological risk factors from strong to weak order were Hg,Cd,As,Pb,Cr,among them Hg was a high ecological risk,the other four kinds of heavy metal were at a lower ecological risk level. [Conclusion]The study can provide scientific reference for ecological environment protection in Xiushan County.