Geochemistry of soil contamination from lead smelters near Eureka Nevada

Eureka, Nevada, was once a boom-mining town with peak production of Pb, Ag, and Au between the 1870s and 1890s. Most of the ores from the area were processed in two smelters located at the north and south edges of the town. Smelter effluent was exhausted in the vicinity of the smelter furnaces with little regard to potential health concerns. For this study, 186 soil samples from sites in the area surrounding Eureka were analysed for 43 elements. Factor analysis and element plots identified 16 smelter-related elements: Ag, As, Bi, Cd, Cu, Hg, In, Mo, Pb, S, Sb, Sn, Te, Tl, W, and Zn. Eight other elements (Ba, Be, Co, Cr, Mn, Ni, U, and V), whose distributions are controlled by the chemical composition of the underlying substrate material, were also evaluated. Of these 24 elements, only six (As, Cd, Pb, Tl, Sb, and Mn) had concentrations that exceeded U. S. Environmental Protection Agency (EPA) estimated residential soil screening levels considered to represent possible health risks. For some analysed elements (In, S, Te, and W) no screening levels have been established. Whether these elements, or any of the others determined, constitute a health risk in the local population is not known.