The contribution of the mining activities on the heavy metals accumulation in soils of the Gejiu tin deposit, Yunnan Province

Mining activity is one of the important factors responsible for heavy metal accumulation in soil. The authors analyzed the relationships between seven kinds of soil heavy metal elements in the Gejiu mining area and the influenced area whose geological conditions is the same as the mining area in comparison with areas unaffected by mining activities. The heavy metal accumulation values and rates of mining activities on soils in the mining area and the influenced area were evaluated one by one in the light of total heavy metals and background-like values in surface soil of the compared area. The results show that the heavy metal accumulation values are in order of Pb>Zn>As>Cu>Cd>Cr>Hg in the mining area and Pb>Zn>As>Cu>Cd>Cr>Hg in the mining influenced area. There is close relationship between Pb, Cd, As, Zn, Cu and mining activities. Pb, Cd and As, characterized by high accumulation and high risk, should be most emphatically controlled in the mining area.