Contamination Pattern of Soils and Surface Water on Vicinity of Abandoned Metalliferous Mine in Southeastern Part of Korea.
Eul-Soo Yun1, Sung-Hak Park2, Ki-Yeol Jung1, Jae-Seng Lee1, Jee-Yeon Ko1, and Yeon-Kyu Park3. (1) Yeongnam Agricultural Research Institute, 1085, Neidong, Milyang, 627-803, South Korea, (2) Chengdo Myeon Agricultural Cooperative, Milyang, Milyang, South Korea, (3) Miryang National Univ, Neidong, Milyang, South Korea
For more than 10 years, most tailings in Korea were left without proper management in their mines so that these tailings have become a serious pollutant within the vicinity of the abandoned mines. To get the basic information on environment restoration for the analysis of residual mine tailings and investigation of pollution pattern of agricultural land and water system in the vicinity of an abandoned metalliferous mine, this study was conducted. The study mine (local name is Guundong) is located in Mahul-ri, Muanmyeon, Milyang City, Gyeongsangnam-do, the southeastern part of Korea. The geological feature of district is Shinra series andesite and mineral deposits of mine contain brimstone. Its main digging minerals include gold, silver, copper, lead, and zinc. This mine was restored 10 years ago by a soil pollution prevention project on county level. The mine area, however, became polluted due to breaking down of the earth's protective cover and mine tailings. Samples of residual mine tailings were collected based on whether or not the restored earth's land cover has been degraded. The sample of soils and water were collected by distance from the mine head. The heavy metals in solid material were extracted by using 0.1N HCI and aqua regia (HNO3£«3HCl : 1 : 3, v/v) and were analyzed into ICP (model Perkin Elmer 3300) The content of heavy metals in mine tailing extracted by 0.1N HCI solution was 188, 2.12, 544, 0.03, and 0.19mg/kg in Cu, Cd, Pb, Cr, and Ni, respectively. That content was merely 1.3¨C18.7% of aqua regia extracted one and the ratio was high in a tailings heap, which weathered due to degradation of restored earth's cover. The heavy metals content of sediment in stream extracted by using aqua regia were 269, 6.6, and 657mg/kg in Cu, Cd, and Pb, respectively. The content was not affected by distance from mine head. The vertical distribution pattern of heavy metals in paddy soils varied among the elements: Cu, Cr, Pb, and Fe in soil were high on the surface but Zn, Ni, Mn, and Cd were high in the subsurface. The content of heavy metals in water was higher in the site directly affected by the mine than in indirectly affected stream, which was natural surface water. Soil pollution degree of this area was classified into levels 3¨C4 for agricultural soil and levels 1¨C2 for industrial area to identify which area should undergo intensive remediation activity for agriculture and environment conservation. Keywords: metalliferous mine, heavy metals, soil and water pollution, sediment