The Effect of the Uranium Content in the Tailings on Some Cultivated Plants

Abstract

Uranium is a radiotoxic and chemotoxic heavy metal. Uptake and accumulation of U has been studied in plants native to uranium mine sites, but not in cultivated plants which are commonly consumed by humans. The objective of this study was better understanding of U uptake and accumulation in cultivated plants and whether different contents of uranium (U) in the substrate affect its concentration in plants and their dry matter mass. Two substrate variants for growing plants, which differed in the uranium content: solid wastes (tailings) and tailings mixed with sand (w/w 1:1). Large amounts of solid wastes (tailings) resulting from the exploitation and treatment of uranium ore from the closed uranium mine Gabrovnica-Kalna, on southeast of Serbia, contained generally 15.33 mg U/kg. In the experiment, three plant species (corn NSSC 231, sunflower N.S. Dukat, and green peas Smederevska Palanka) were grown in pots on the four substrate variants during 40 days. Substrate was suffused by drinking water (DW) and "uranium water" (UW), which issue out from the mine, contained 0,053 mg U/ dm(3). Obtained results show that when UW was added to tailing concentration of U in plants increased. When the content of U in the substrate was lowered by adding sand, the concentration of U in plants decreased, though was significantly higher in comparison to the variants to which DW was added. Dry matter mass was higher in variants where UW was used. Concentration of U was significantly higher in root than in above-ground parts.