Uranium concentration in plants developed on agricultural soils and waste dumps in Cunha Baixa mine site (Mangualde)

Abstract

The uranium concentration and the bioco­centration capacity (BC) in several plant species (aboveground part) were evaluated and compared among species grown on soils developed on waste materials (Pinus pinaster, Cytisus striatus, Cytisus multiflo­rus) and agricultural soils (Zea mays L., Phaseolus vulgaris L., Lactuca sativa L.) from the surrounding area of Cunha Baixa mine (Mangualde).

The species colonizing waste materials are well adapted to the substratum, which contains high total and available uranium concentration (118 mg kg^-1 and 43 mg kg^-1 , respectively). Pinus pinaster concentrated more uranium (13.9 mg kg^-1) than the spe­cies of genus Cytisus. As a consequence, and also due to the effective vegetation cover these plants can contribute to the sta­bilization of mining wastes dumps. Lactuca sativa concentrated more uranium (on ave­rage, 5.37 mg kg^-1 dry weight) than the other cultivated plants. None of the studied species was uranium accumulator (BC <1), even if they are growing in high-contaminated soils and irrigated with con­taminated water.