武汉市郊区设施蔬菜地土壤重金属含量及其生态风险

采用野外调查采样和室内分析相结合的方法,对武汉市郊部分设施蔬菜地土壤5种重金属砷(As)、汞(Hg)、铬(Cr)、镉(Cd)、铅(Pb)的累积现状和潜在生态风险进行了分析评价.结果表明,研究区土壤中As、Hg、Cr、Cd、Pb的平均含量分别为0.06、0.15、19.85、1.07、5.44 mg/kg,其中Cd和Hg的平均含量分别达到湖北省土壤背景值的9.41和2.36倍;设施蔬菜地土壤中不同重金属的单因子污染状况具有Cd>Hg>Cr>Pb>As的特征,就综合污染指数而言,Cd元素是污染发生的主要贡献因子;从多种重金属潜在综合生态风险指数(RI)来看,研究区仅有18.23%的采样点达到中等生态风险,其余样点的潜在生态风险指数在轻微风险水平范围内.图4表3参15

Contents of Heavy Metals in Greenhouse Soil Around Wuhan Suburb and Their Potential Ecological Risk

The contents of five heavy metals(As,Hg,Cr,Cd,Pb) in greenhouse soils of Wuhan,China were investigated to provide basic information for controlling heavy metal pollution in greenhouse soil.The Hakanson ecological risk index was applied to assess the potential ecological risk of the heavy metal pollution.The results showed that the concentrations of As,Hg,Cr,Cd,Pb in the studied areas were 1.07,0.15,5.44,0.06,19.85 mg/kg,respectively,and Cd and Hg were 9.41 and 2.36 times,respectively higher than the basic background values of Hubei Province.The individual pollution factor of each heavy metal in the studied soils followed the order of Cd > Hg > Cr > Pb > As.Cd was the most potential ecological risk factor in the investigated areas.Based on the result of comprehensive potential ecological risk assessment,there were only 18.23% of the studied areas reached the moderate level,all other areas,however,were lower than mild level.Fig 4,Tab 3,Ref 15