Mercury speciation determined by thermo-desorption analysis at two sites contaminated by mining

Historic mercury mining represents an envinrnmental threat due to high llg concentration in waste materia|. Mercur1'ores \\'ere mined for more than l50 years at t\ťo siles in the centr.a| ('zech Republic, hut thc extent of Hg contamination in the vicinity of former l-lg mining sites has not been yet inr'stigatď. The objectives of the study weÍe to eva|uate thc Hg sorrrces in mine wastes. assess the extent of Hg contamination in historical ntining area ancl to cstimate potential mohility of Hg in the mine waste and soils. The method of thermal tlesorption in combination tvith Í(.P-oES (TDA-lCP.oEs) has been app|ie<l to dctermine llg speciation irr solid samples. Mine rvaste matďa| was samp|e<| at two mining sites. .|edová Hora and Svatá, in ccntral Bohemia. Three soi| profi|es were col|cclď to caphlre likely high and low impact sites rvithin the mining area at Jedová l{ora' Database of thcmto-<|esorption cun,cs o[ I{g chemica| conrpottnds ant| rcference materia|s was crcated for the TDÁ ftrr comparativc purposes. Both mine wastes and soils collected near the llg nines were highly elcvated in total l-lg corcentrations (up to 120 pg g-r and l0 pg g-', respectively). Soils exhibited the highest tlg concentrations mostly in subsurface Ah soil horizons. Higher lJg concentrations in Ah horizons relative..