Heavy metals and arsenic in an abandoned barite mining area: ecological risk assessment using biomarkers

This study identifies a source of heavy metal pollution in the Tarnia-Ostra area, Suceava County, Romania, using both chemical and biological techniques. Samples collected from the sterile dumps and the surrounding soil were digested and analyzed for total metals and arsenic by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and atomic absorption spectrometry (AAS). High concentrations of heavy metals, such as copper (3.12 g/kg), arsenic (0.68 g/kg), lead (2.67 g/kg), zinc (0.43 g/kg) and barium (0.54 g/kg), found in that region, may pose a high risk to the environment and public health through the food chain. The large amounts of Cu, Fe, Pb, Zn and As of the collected samples diminished much the germination of wheat (Triticum aestivum L.), used in this study as a marker of toxicity. However, after the removal of the heavy metals by treating the aqueous extracts with sodium hydroxide solutions, the germination parameters returned to normal. The quantification of heavy metal levels by ICP-OES provides a better understanding of the potential ecological risks and contamination status of the tailings dumps. Instead, wheat germination tests can be reliable and inexpensive biological methods to prove the harmful effect of heavy metals and arsenic on plants.