Abstract

In order to evaluate the degree and extent of heavy metal pollution and the environmental impacts of abandoned Cu mines in Goseong-gun, soils and paddies were collected from the mine area and have been analysed for heavy metal contents. The heavy metal contents were much higher in mountain soils than in paddy soils. Total content of heavy metals decreased in order of Cu>Zn>Pb>As>Cr>Cd in mountain soils whereas Zn>Pb>Cu>Cr>As>Cd in paddy soils. The extractable amount of heavy metals by 0.1/1N HCl decreased in order of Cu>Pb>Zn>As>Cd>Cr in mountain soils whereas Pb>Cu>Zn>As>Cd>Cr in paddy soils. Although the extraction ratios were highly various depending on the sampling site, their average values were in order of Cd(16%)>Pb(10%)>Cu(9%)>As(4.5%)>Zn-Cr(≤2.5%). The soils investigated were enriched in heavy metals relative to the averages of earth crust as in order of As≥Cd>Pb>Zn>Cu>Cr. Pollution index calculated from total or extractable heavy metals of soils indicated that the heavy metal pollution was restricted to mountain soils around abandoned Cu mines, especially the Samsan I mine. The metal contents of brown rice showed no significantly contaminated level as follows; As nd~0.87 mg/kg, Cd 0.02~0.34 mg/kg, Cu 1.01~6.25 mg/kg, Mn 13.4~43.2 mg/kg, Pb 0.09~2.83 mg/kg, and Zn 16.5~79.1 mg/kg. From the extraction and dispersion properties of heavy metal with the soil pH (4.5~7.8), it can be deduced the conclusion that the heavy metal pollution is spreading in the study area mainly by the detrital migration of waste ore and gangue minerals rather than the dissolution and circulation of heavy metal.

Keywords Goseong Cu mine, Soil, Brown rice, Heavy metal, EF, PI