Distribution and pollution assessments of heavy metals in soils in Zhuzhou, Hunan

Abstract：Investigation and assessments of pollutions of heavy metals such as Cu, Pb, Zn, Cd, Cr, Hg and As in Zhuzhou City were carried out. The results show the following： (1) The Cd pollution of all the 60 samples from Zhuzhou City has been heavy, the pollution of Cu, Hg and As is moderate, and the pollution of Pb, Zn and Cr is slight. The Nemerow comprehensive pollution index also shows heavy pollution. (2) The heavy metal contents in soils of different land use types decrease as follows： the Cu, Zn, and Cr contents decrease from paddy field→vegetable field→dry land; Pb, Hg and As, dry land→paddy field→vegetable field; and Cd, vegetable field→dry land→paddy field. (3) The heavy metals content with different soil types from high to low is as follows： The contents of various heavy metals in different soil types decrease as follows： the contents of Zn, Cd and As decrease from sandy Chao soil→clay soil→red soil; Pb and Hg, clay soil→sandy Chao soil→red soil; Cr, red soil→sandy Chao soil→clay soil; Cu, sandy Chao soil→red soil→clay soil.