Investigations of Pb and Cu Isotopes to Trace Contamination Sources from the Artificial Shihwa Lake in Korea

Abstract

Jeong, H.; Choi, J.Y.; Lee, J., and Ra, K., 2020. Investigations of Pb and Cu isotopes to trace contamination sources from the artificial Shihwa Lake in Korea. In: Malvárez, G. and Navas, F. (eds.), Global Coastal Issues of 2020. Journal of Coastal Research, Special Issue No. 95, pp. 1122-1127. Coconut Creek (Florida), ISSN 0749-0208.The concentrations of heavy metals and Pb and Cu isotopes in sediments from five streams (A–G) around the Shihwa National Industrial Complex in Korea were investigated with the aim of identifying sources of metal pollution. The average concentration of Zn (21,106 mg/kg) was the highest, followed by Cu (2,804 mg/kg), Ni (2,126 mg/kg), Pb (897 mg/kg), Cr (807 mg/kg), As (18 mg/kg), Cd (8.0 mg/kg), and Hg (1.4 mg/kg). The concentrations tended to be highest in sediments from stream G. The 206Pb/207Pb and 208Pb/206Pb ratios of stream sediments ranged from 1.1302 to 1.1626 and 2.0983 to 2.1990, respectively. The Pb isotopes in stream sediments showed linear trends both Chinese Pb ore and Korean Pb–Zn Ore deposit. The Pb isotopic composition overlapped with Shihwa road dust values. The δ65CuAE647 values of stream sediments ranged from –0.16‰ to 0.64‰, clustering in two groups, one relatively enriched in the light Cu isotope (0.08‰–0.13‰) and another enriched in the heavy Cu isotope (0.37‰–0.48‰). Our results indicate that streams F and G are relatively enriched in heavy Cu isotopes. 208Pb/206Pb vs. δ65CuAE647 plots indicate that the two branches of the Shingil stream (E and F) are noticeably distinguished, with their isotopic compositions suggesting different pollution sources. The Cu and Pb isotopic compositions reflect those of road dust, and suggest that the stream sediments were affected by road dust transported in stormwater runoff. Thus, road dust may be a potential source of metal pollution in the stream sediments of industrial regions in Korea.