对中国东北北部22个县市黑土可能发生重金属污染的污染源进行了系统调查；对土壤样品中Cd、Pb、Cu、Zn进行检测分析，4种重金属的检出范围依次为0013-231mgkg，1052-5748mgkg，4213-22710mgkg和995-4618mgkg。结合单污染指数评价法和表底土比较2种方法进行污染评判，结果表明，土壤样品中重金属Cd的污染最为明显，其污染多集中在中度和重度水平。对于重金属Pb、Zn和Cu的污染用单污染指数评判没有准确反映污染的真实情况，同时说明不同评判方法的精确性有较大的差距。用表底土比较法对Pb、Cu、Zn3种重金属进行评判，发现其在采样区域的污染水平仍非常明显，依次有571%，210%和533%的表土样品受到这3种重金属不同程度的污染。大部分受到污染的土壤样点大多集中在市内工业区附近土壤和城乡结合部菜地。

Systematic investigations were carried out into the sources of heavy metal pollution in phaiozem throughout twenty two counties/cities in northeast China. Heavy metals of Cd, Pb, Cu, Zn in the soil samples were measured by atomic absorption spectrophotometry, and they ranged from 0 013-2 31 mg/kg,10 52-57 48 mg/kg, 42 13-227 10 mg/kg and 9 95-46 18 mg/kg respectively. According to the evaluation of single contaminative index and the comparing of topsoil and subsoil, it was found that 42 9 percent of the samples was polluted by Cd, and most of the pollutants were assembled in middle and serious levels. The polluted situation of Pb, Zn and Cu was not reflected accurately by the evaluation of single contaminative index. It was showed that there is great difference between the two methods of evaluation. The contaminative phenomenon was very obvious by the evaluation of comparing topsoil and subsoil. 57 1%, 21 0%,53 3% of topsoil samples, respectively, were polluted by Pb, Cu and Zn. Most of the polluted samples were distributed in the fields in suburbs and in the areas near the industrial parts of cities.