The contribution by anthropogenic sources to abnormally high Zn concentrations in soils with naturally abundant Zn was investigated at a contaminated site surrounding a Zn smelter in eastern Korea. Nineteen soil samples were collected within a 2 km radius of the smelter, and analyzed for metal concentrations and Pb isotope ratios using an inductively coupled plasma-optical emission spectrometer and -mass spectrometer, respectively. Higher Zn concentrations in locations closer to the smelter implied that the smelter was the source of the Zn pollution. Lead isotope ratios (206/207Pb) from soil samples assumed to be unaffected by the smelter were higher than those found in the contaminated area, suggesting that the raw materials of Zn concentrates (ZnS, sphalerites) and smelting by-products from the smelter with low 206/207Pb ratios were the anthropogenic Zn source impacting the area. To verify this finding, the mineralogical forms of Zn found in the different soil fractions were investigated by X-ray diffraction analysis, scanning-electron-microscope energy-dispersive spectrometer analysis, and sulfur element analysis. Since approximately 50% of Zn concentrates have particle sizes less than 0.044 mm, the observation of sphalerites and elevated sulfur concentrations in the finer soil fraction (< 0.044 mm) provide substantial support to the hypothesis that the deposition of airborne Zn-containing dust from the smelter is responsible for the high Zn concentration in the area.
Bibliographical noteFunding Information:
We thank Dr. Kyung Su Park, Sung Hwa Choi, and Eun Ji Song at the Advanced Analysis Center, Korea Institute of Science and Technology for their help during the chemical analysis. This work was supported by the Geo-Advanced Innovative Action (GAIA) Project (#2015000540001) of the Ministry of Environment, Korea.
© 2017 Elsevier B.V.
Copyright 2020 Elsevier B.V., All rights reserved.
- Environmental forensics
- Lead isotope
- Source identification
- Zinc contamination
- Zinc smelter
ASJC Scopus subject areas
- Environmental Engineering
- Environmental Chemistry
- Waste Management and Disposal