Abstract:

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.

Key words: northern part of northeast China, phaiozem, heavy metal, pollution