The Variability of Arsenic and Other Risk Element Uptake by Individual Plant Species Growing on Contaminated Soil

Abstract

Surrounding Kutná Hora (Czech Republic) are areas characterized by former silver mining activity. Therefore, a high level of risk elements was reported in soil close to the historical mines. The Aqua Regia extractable (i.e. “pseudo-total”) element values in soils exceeded the Czech threshold values representing 30 mg kg−1 As, 1.0 mg kg−1 Cd, 200 mg kg−1 Cr, 80 mg kg−1 Ni, 140 mg kg−1 Pb and 200 mg kg−1 Zn, by up to 15-fold for zinc, 30-fold for cadmium, and even 80-fold for arsenic. Mobile portions of elements determined in 0.11 mol L−1 CH3COOH solution did not exceed 1% of the “pseudo-total” element content for As, Cr, and Pb. Diversity of vegetation cover growing at the contaminated soil close to the former mine, as well as element uptake by aboveground biomass of individual plant species, was investigated. Plant species growing in these soils represented an ordinary ruderal plant community of 29 species without occurence of metallophytes. Moreover, the element concentrations in above-ground biomass of plants were low. Transferfactors, given as a ratio of element content in plant and its “pseudo-total” content in soil, varied from 0.0003 to 0.003 for As, from 0.001 to 0.174 for Cd, and from 0.016 to 0.169 for Zn. Evidently, the analyzed plant species are characterized by low ability to take up the risk elements and translocate them to above-ground biomass and the potential risk for animals consuming this biomass is negligible.