Cadmium and zinc in polluted mining soils and uptake by plants (El Losar mine, Spain)

Total cadmium (Cd) and zinc (Zn) contents in soils around mine spoils ranged from 1.91-80 and 98-9200 mg/kg with an arithmetic mean of 28 and 4079 mg/kg, respectively. These amounts are much higher than the background levels. Higher concentrations of the labile form of Cd (20.7%) and moderate levels for Zn (7.6%) indicate a high environmental threat by these toxic elements. Cadmium contents in some plant species (Antinoria agrostidea, Linaria spartea, Linaria supina, Spergularia rubra, and Gallium verum) sampled near mine spoils are very high in relation to the overall mean plant contents cited in the literature. Among them, Antinoria agrostidea accumulates a higher Cd amount showing a higher accumulation factor than other plant species, such as some Brassicace species grown in soils with a similar concentration of Cd available (El Losar site).