Heavy metal pollution and pesticide residues in soils of Kunming area

Investigations and survey were carried out to determine heavy metal pollution(Cd、Cu、Pb、As、Cr and Hg)and pesticide residues(666、DDT、methamidophos、omethoate)in soils of Kunming area.Their sources were probed into and severities assessed.The results indicate that the soils are polluted with Cd、Cu、As and Hg to a varying extent.The pollution by Cd is the most serious and then followed in the order of Cu>Hg>As>Pb>Cr.The comprehensive assessment shows that the heavy metal pollution of the soil is medium in level.Residues of organic chlorin pesticides were found in the soil,and so were organic phosphor pesticides,though quite low in content.