Investigation and Risk Assessment of Heavy Metals Contamination around an Abandoned Metal Mine in Korea

Abstract

Recently, heavy metals contamination of the agricultural soil and crops surrounding mining areas has been identified as one of the most serious environmental problems in South Korea. The Ministry of the Environment in Korea conducted a Preliminary National Environmental Health Survey (PNEHS) in abandoned metal mines in 2007. The priority for a subsequent detailed examn. was ranked from the results of PNEHS. The studied mine which was ranked as being of the highest priority is located in the Midwestern part of Korea and was operated from 1911 to 1985. In this study, the contamination levels of the heavy metals in the abandoned metal mine were investigated. From the results, the av. daily dose (ADD), target hazard quotient (THQ) and target cancer risk of the heavy metals were evaluated. The concn. of arsenic (As) in all of the tailings from the mine was higher than its countermeasure std. of Korea. In particular, the highest concn. of As, 330 mg/kg, was up to 15 times higher than its countermeasure std. The av. concn. of As in agricultural soils was higher than the warning std. of Korea, and higher than its countermeasure std. at six sites. The av. concns. of the analyzed heavy metals in agricultural soil were below the warning std., but concns. of cadmium (Cd) and lead (Pb) at 4 sites were higher than its warning std. The av. concn. of As in surface water exceeded the warning std. of Korea. The value of the THQ of As for the tailings was higher than the health protection std. 1. The value of THQ of As for the farmlands was lower than the std., while the hazard index (HI) of As was higher than the std. The value of target cancer risk (TCR) of As, 6.44 × 10-4, were higher than the health protection std. of a lifetime risk for TCR at 1 × 10-6. This suggests that the residents around the metal mines are exposed to As pollution with a carcinogenic risk. [on SciFinder(R)]