The distribution of total and methylmercury concentrations in soils near the Idrija mercury mine, Slovenia, and the dependence of the mercury concentrations on the chemical composition and organic carbon levels of the soil
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Although the mining activity of the Idrija mine in Slovenia ceased in 1995, a large amount of mining dregs containing high concentrations of mercury remains in the area. The mining dregs were transported with river flow and deposition along the Idrija River. To estimate the dispersion and change in the chemical form of mercury, a total of 28 soil core samples were taken around the river. The individual core samples were separated into layers for the analysis of their chemical composition, carbon contents, total mercury (T-Hg) and methylmercury (MeHg) concentrations. The chemical composition measured by X-ray fluorescence spectrometry was useful to estimate the dispersion of tailings: the fluvial terrace soil had a chemical composition similar to that of the tailings and could be distinguished clearly from the forest soil. The highest T-Hg concentration, 1,100 mg kg−1, was observed in the fluvial terrace soil near the mine. Although the concentration decreased gradually along with distance from the mine, concentrations higher than 200 mg kg−1 of T-Hg were still observed in the fluvial terrace soil approximately 20 km downstream from the mine. In the vertical distribution of T-Hg in the hillslope soil, a higher value was observed in the upper layers, which suggests the recent atmospheric deposition of mercury. The concentration of MeHg was the lowest at the riverside and higher in the hillslope soil, which was the opposite of the T-Hg distribution. The total organic carbon content tracked similarly with the distribution of MeHg and a linear relation with a significantly high correlation coefficient was obtained. The distinction may be related to the different dispersion process of mercury, and the organic carbon contents may be an important factor for MeHg formation.
KeywordsTotal mercury Methylmercury Idrija mercury mine Soil TOC XRF
This work was supported by Grants-in-Aid (No.15404003 and No.18404001) for Scientific Research from the Japan Society for the Promotion of Science.
- Akagi H, Nishimura H (1991) Speciation of mercury in the environment. In: Suzuki T, Imura N, Clarkson TW (eds) Advances in mercury toxicology. Plenum Press, New York, pp 53–76Google Scholar
- Bonzongo JC, Lyons WB, Hines ME, Warwick JJ, Faganeli J, Horvat M, Lechler PJ, Miller JR (2002) Mercury in surface waters of three mine-dominated river systems: Idrija River, Slovenia; Carson River, Nevada; and Madeira River, Brazilian Amazon. Geochem Explor Environ Anal 2:111–119CrossRefGoogle Scholar
- Hall BD, St. Louis VL (2004) Methylmercury and total mercury in plant litter decomposing in Upland forests and flooded landscapes. Environ Sci Technol 38:5010–5021Google Scholar
- Hines ME, Faganeli J, Adatto I, Horvat M (2006) Microbial mercury transformations in marine, estuarine and freshwater sediment downstream of the Idrija Mercury Mine, Slovenia. Appl Geochem 21:1924–1939Google Scholar
- Munthe J, Lyvén B, Parkman H, Lee YH, Iverfeldt Å, Haraldsson C, Verta M, Porvari P (2001) Mobility and methylation of mercury in forest soils development of an In-Situ stable isotope tracer technique and initial results. Water Air Soil Pollut: Focus 1(3-4):385–393Google Scholar
- Tomiyasu T, Matsuo T, Miyamoto J, Imura R, Anazawa K, Sakamoto H (2005) Low level mercury uptake by plants from natural environments–mercury distribution in Solidagoaltissima L. Environ Sci 12:231–238Google Scholar
- Wiener JG, Knights BC, Sandheinrich MB, Jeremiason JD, Brigham ME, Engstrom DR, Woodruff LG, Cannon WF, Balogh SJ (2006) Mercury in soils, lakes, and fish in Voyageurs National Park (Minnesota): importance of atmospheric deposition and ecosystem factors. Environ Sci Technol 40:6261–6268CrossRefGoogle Scholar