许昌市道路绿地土壤重金属污染及潜在生态风险评价

Assessment of Pollution and Potential Ecological Risk of Heavy Metals in Soils of Road Green Space in Xuchang

为探明道路绿地土壤重金属污染状况和潜在生态风险,采用地累积指数法、潜在生态风险评价法对许昌市道路绿地表层土壤重金属Pb、As、Zn、Cu、Ni和Mn进行了分析.结果表明:除Mn外,其他5种重金属的含量均值均高于河南省土壤环境背景值;土壤重金属污染程度为轻度污染和无污染;潜在生态风险指数排序为As>Pb>Cu>Ni>Zn>Mn;综合潜在生态风险指数以市区东部、东南部、西北部较高,生态风险程度整体属轻微.As、Pb、Cu在6种重金属中的生态风险贡献率为76.15%,是需要重点关注的生态风险因子.

To ascertain the pollution status and potential ecological risk of heavy metals in topsoils of major road green space in Xuchang,the pollution characteristics and ecology risk of Pb,As,Zn,Cu,Ni and Mn were analyzed by using the method of geologic accumulation indices and the potential ecological risk evaluation.The results showed that:The contents of Pb,As,Zn,Cu and Ni were all higher than the corresponding background value in Henan Province,while the content of Mn was lower than background value.The mean value of I geo showing no or light pollution.The order of mean values of E i r was As>Pb>Cu>Ni>Zn>Mn.There were three high value areas of RI,distributing in eastern area,southeastern area and northwestern area.The mean value of RI showing a light degree in integrated ecological risk.Among the six heavy metals,the total contribution rate of As,Pb and Cu in the whole potential ecological risk was 76.15%,indicating that these three heavy metals were the main risk factors.