“Contamination Assessment of Abandoned Mines by Integrated Pollution Index in the Han River Watershed”

Abstract

Heavy metal contamination from abandoned mine areas is a major threat for the environment. The study objec- tive was to categorize the most polluted mine areas among 44 mine sites at the four cities of Chungcheongbuk-do province in South Korea. Both water and soil samples were collected from the mine area. The pH of the water and soil ranged from 3.6 to 8.5 and from 4.1 to 9.1 respectively. A significant amount of arsenic (As), cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb), zinc (Zn) and mercury (Hg) occurred in soil samples collected from the mine areas (0.2 to 42.4, 0.7 to 8.6, 10.7 to 430.2, 5.8 to 49.8, 2.1 to 122.8, 37.4 to 359.4 and 0.2 to 11.4 mg kg-1 respectively). The surrounding available waters also carried high contents of Cd, Cu, Pb and Zn, generally exceeding the fresh water acute and chronic criteria. Each mine site was ranked according to the Integrated Pollution Index (IPI). The normalized pollution index (PIn) for water and soil, and the Survey Index (SI) were used to determine IPI. The highest polluted mine site exhibited an IPI value of 0.6394. IPI was introduced to prioritize the research sites for further precise investigation.