河南农田土壤重金属污染状况及其评价

在河南境内取自农田土壤102例表层样品，分析了其中的Cr、Zn、Cu、Pb、Ni、As等8种重金属元素的含量。结果表明：河南农田土壤中除Cr偶有超出我国《土壤环境质量标准》（GB15618—1995）二级标准的土样外，其他项目均不超标，重金属污染由高到低排序为Cr〉Zn〉Ni〉Cd〉Hg〉Cu〉Pb〉As。重金属元素在河南各土壤利用类型中分布规律不明显，按4种主要土壤利用类型考查来看，重金属污染程度大小排序为：果园地〉水田〉菜地〉其他粮田；河南农田土壤综合污染指数总平均为0．981，土壤总体为尚清洁，重金属污染处于警戒水平；河南农田土壤中Cr含量较高的土壤主要是粗骨土与石质土，其天然本底值较高。

On Heavy Metal Pollution Status and Its Assessment for the Farmland Soil of Henan Province

In deriving 102 surface samples from farmland soil of Henan within the territory, it has been analyzed for element contents of 8 kind heavy metal, such as Cr , Zn , Cu , Pb , Ni. Result indicates that they do not go beyond our country ＂Environmental quality standard for soils＂ except Cr occasionally to exceed, the order in decreasing pollution potential is Cr, Zn, Ni, Cd, Hg, Cu, Pb, As. Although distribution of heavy metals in the samples is not well defined, the data suggests the order in declining pollution potential of orchard soil, paddy field, vegetable field and other grain producing area. The average comined pollution index is 0. 981, indicating that most of the soil samples are clean and that pollution of heavy metal for some areas is at the alert level. In Henan farmland soil, contents higher Cr soil is that thick bone soil and stone are local , whose natural background values is higher mainly.