Distribution of trace elements in soils at the abandoned Sb deposits of Dúbrava and Popro

Occurrence of the increased concentration of potential toxic elements (As, Sb, Pb, Zn) in soils is of a great environmental concern in the vicinity of the abandoned Sb deposits (Dúbrava and Popro ). We have shown that the soils are strongly impacted by the point sources of contamination (old mine drainages, tailing impoundments, and waste-rock dumps). Oxidation of sulphide minerals in the mine tailings may induce the other geochemical processes such as acidification and subsequent mobilization of trace elements into the surrounding environment. High Sb and As concentrations were observed in the soils collected at the Dúbrava and Popro mine sites, reaching up to 9619 mg.kg-1 (Dúbrava) and 2484 mg.kg-1 (Popro ), respectively, but relatively high concentrations of Pb and Zn were also detected. Abundant secondary minerals consisting mainly of Fe, Sb(Fe) and Fe(Sb) oxyhydroxides with variable and high Sb, Fe and As contents in their structure were identified in the soil samples. Furthermore, these oxyhydroxides appear to be relatively stable, and thus they might reduce the mobility of trace elements through the soils horizons.