我国几个工矿与污灌区土壤重金属污染状况及原因探讨

对我国几个重工业区、矿区、开发区以及污灌区土壤重金属污染状况的调查结果表明，土壤重金属含量绝大部分高于土壤背景值，Cd、Zn等明显超标，某些重金属元素含量间还存在着一定的伴生规律。土中浸提态Cd、Zn含量与土壤pH值呈负相关。土壤中的重金属主要来自于污灌、金属矿藏开采、污泥利用以及大气飘尘等。金属冶炼厂附近土壤中Pb、Zn、Cd含量皆与离污染源距离呈密切的指数相关（R^2＞0.9）。

Soil contamination and sources of heavy metals at individual sites of industry and mining associate with wastewater irrigation in China

An investigation on soils contaminated with heavy metals was carried out at heavy industrial areas, metal mining and tilling sites, and farmland with sewage water irrigation, respectively. The result indicated that concentrations of the most metals from the polluted sites were higher than those from backgrounds, Cd and Zn should be paid more attention since they were over the Governmental Standards in China for limitation of soils in agricultural practices. Some companion relations existed between various metals, such as Pb and Ni, Cr with Ni and Zn, Cu with Zn and Ni, the negative correlation between extractable contents of Cd and Zn and soil pH values was found. The soil metals mainly come from untreated sewage water irrigation, disposal of tailings or slurry from metal ore mining. Besides, metal dust deposition was one of the contributors as well in the vicinity of metal smelters or heavy industrial areas since a good exponential correlation ( R \+2>0 9) between the contents of Pb, Zn or Cd and the distances from the source existed.