Assessment of heavy metal contamination and its ecological risk in the surface sediments along the coast of Korea

Abstract

We studied the spatial distribution of heavy metal contamination and its ecological risk assessment in sediments from the Korean coast. Surface sediments collected from 12 coastal zones of Korea (total 200 sediment samples) along the west, south and east coast of Korea have been analyzed for heavy metals including Cr, Co, Ni, Cu, Zn, As, Cd, Pb and Hg using ICP-MS. Mean concentrations were 58.3 mg/kg for Cr, 10.2 mg/kg for Co, 24.3 mg/kg for Ni, 36.5 mg/kg for Cu, 122 mg/kg for Zn, 9.1 mg/kg for As, 0.25 mg/kg for Cd, 35.0 mg/kg for Pb and 0.046 mg/kg for Hg, respectively. Sediments sampled from heavily industrialized areas such as Shihwa, Masan, Gwangyang and Ulsan were highly contaminated with Cu, Zn, Cd and Hg. Significantly positive correlation among metals were observed (p<0.01). This suggests that sources of metal contamination were mainly attributed to anthropogenic inputs from surrounding environment, especially national industrial complexes that consist of iron, steel, machinery, electronics and petrochemical. The results of metal assessment indices indicated that the Korean coast sediments were moderately contaminated with Cu, Zn, As, Cd, Pb and Hg. The mean of metal enrichment levels decreased following the order of Cu>Hg>Cd>Zn>As>Pb>Co>Cr>Ni. Based on the comparison with sediment quality guidelines (SQGs), Cu, As and Zn levels at more than 40% of sediment samples exceeding TEL values are likely to result in potential adverse effects on sediment-dwelling organisms.