The result of the 360-year history of mining activity in the Upper Meža valley is soil heavily contaminated with cadmium (Cd) and lead (Pb). In areas of high pollution, local residents often have gardens. Heavy metals accumulate in the edible parts of vegetables and thus enter the human food chain. With various amendments, we can potentially reduce the bioavailability of toxic pollutants to living organisms. In the pilot study, we wanted to determine whether the amendments we selected on the basis of previous studies have an effect on the mobility and bioavailability of certain heavy metals, and to investigate the possibilities of their further use for the remediation of contaminated soils. In a pot experiment with beetroot (Beta vulgaris L.), five different soil additives were tested in order to determine the differences in the accumulation of Cd and Pb in the above-ground and underground parts of the selected plant. We chose biochar, zeolite, paper mill sludge, compost and vermiculite. We prepared mixtures of contaminated soil and selected additives. Soil amendments failed to reduce the transfer of Pb or Cd from contaminated soils to beetroot below the threshold value. In the case of lead, this can be explained through originally low bioavailability and mobility in relation to its high total content, which can be partially attributed to the properties of the element itself. We believe that pH may be responsible for the maximum concentration of the exchangeable fraction of cadmium.
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