Mercury Distribution in Soil Profiles Polluted by Lead Smelting

The smelting industry is one of the most important sources of anthropogenic contamination of the environment today. In the vicinity of nonferrous metal smelters, high concen-trations of toxic compounds (especially metals and metal-loids) have been detected in soils and vegetation (e.g., Ettler et al., 2005a; Suchara and Sucharová, 2002; Svoboda et al., 2000). In these instances, smelter emissions are as-sumed to be the dominant source of soil contamination (Ettler et al., 2005a,b). In the vicinity of a Pb smelter, Ettler et al. (2004) found that metals such as Pb strongly migrate downwards in soils and accumulate in mineral soil hori-zons. The form of metal in smelter emissions varies signifi-cantly. The smelter emissions in traditional Hg-mining areas are mainly composed of elemental Hg0, coming from the vapor produced and emitted by roasting furnaces (Fernández-Martı́nez et al., 2006). In contrast, the emis-sions from Pb smelters are mainly composed of Pb-sulfates and Pb-chlorides, and no specific Hg-bearing phases were detected in fly ash by the mineralogical methods (Ettler et al., 2005b). Nevertheless, soil Hg concentrations can be high enough to be considered a severe contaminant even in areas polluted by Pb smelting (Rieuwerts and Farago, 1996). Interestingly, little attention has been given to Hg concentrations in soils and vegetation in the vicinity of primary and secondary Pb smelters. This article describes the differences in total Hg concentrations between undis-turbed forest and tilled soil profiles affected by a Pb smelter at Přı́bram, Czech Republic. Mercury sources and the vertical migration of mercury through soils are discussed. Materials and Methods The mining and smelting district of Přı́bram, Czech Republic, is known for its Pb-Ag-Zn polymetallic mineral deposits, which were mined and processed from the Middle Ages until the 1970s. Since 1974, the Pb smelter in the district operates as a secondary smelter that processes Pb scrap, mainly car batteries (more information on smelter operations is recorded in Ettler et al., 2001, 2005b). Top-soils in the area are highly contaminated by Pb (up t