Concentrations of heavy metals in plants grown on polluted mining soils (Loma Charra mine, Spain)

Evaluation of heavy metal accumulation in plants is of environmental importance due to its toxicity effects in humans and other biota. Soils and plants were sampled in a polluted site around a Pb-Zn(Cd) mine. Total metal contents in the soil indicate a gross degree of pollution in relation to background levels. Soil Cd shows high mobility and availability and consequent high environmental risk. The range of cadmium content in plants (<0.05?3.6 mg/kg) is relatively low, although higher than the reference plant content, and none of the sampled plant species hyperaccumulated Cd, Pb and Zn. Metal concentration in plants exceeds the MLRL (maximum level recommended for livestock), and the barley crop exceeds the EU limit, which indicates a risk of food chain contamination in the studied area.