Historical record of metal accumulation and lead source in the southeastern coastal region of Korea

Concentrations of heavy metals and Pb isotopes were measured in the 1-M HCl leaching fraction of core sediments spanning the last 400 years. This sedimentary record of pollution history in metal concentrations shows a good correlation with the increases in industrialization, urbanization, and energy consumption since 1901s. Notably, the Pb concentration and the ²⁰⁷Pb/²⁰⁶Pb and ²⁰⁸Pb/²⁰⁶Pb ratios were constant before the 1910s (16.7 μg/g, 0.844, and 2.098, respectively), whereas they increased steadily up to 21.9 μg/g, 0.848, and 2.101 after the 1910s. The correlations between Pb isotope ratios (²⁰⁶Pb, ²⁰⁷Pb, and ²⁰⁸Pb) showed different linear regression trends for core sediments before and after the 1910s, indicating differences in Pb sources. Our interpretation suggests that the source of anthropogenic Pb in Korean coastal region and the Yellow Sea shelf was presumed to be Chinese coals or ores, which have also played a major role as sources of atmospheric particulate Pb.