Toxicity Assessment of Contaminated Soils from a Mining Area in Northeast Italy by Using Lipid Peroxidation Assay.

Contamination by heavy metals in soils may strongly affect the environmental quality. Lipid peroxidation caused by heavy metals in plants was investigated as a relevant bioassay of toxicity. Soils and wild plants (dandelion and willow) were collected from an abandoned mine area in northeast Italy, and the concentration of different heavy metals (Ni, Cr, Cu, Pb, Zn, Fe and Mn) were measured and analyzed. Soils affected by mining activities presented total Zn, Cu, and Pb concentrations (2566, 3975, 20,815 mg kg−1 respectively) above toxic thresholds, and 58% for Fe. Heavy metal-induced oxidative stress was evidenced by the generation of reactive radicals, followed by an increase in malondialdehyde (MDA) production up to 41.64 μM in willow leaves. We found that MDA concentration in plant tissues differed significantly among species and plant organs. The higher concentration of metal in soil corresponded with the higher concentration of MDA in the plant. The combined results of metal concentration, MDA content and translocation coefficients in plants show that the investigated plants are rather highly tolerant towards environmental pollution. This suggests that they could be useful in phytoremediation of metal contaminated sites.