Phytoremediation potential of native plant species for heavy metal contamination in the abandoned Kolar gold fields, Karnataka, South India

Abstract This study focuses on the concentrations and migration-transformation mechanisms of metalloids in a gold mine located in the Kolar region of the Karnataka metallogenic belt. We analyzed common metal(loid)s, including arsenic (As), gold (Au), copper (Cu), lead (Pb), and zinc (Zn), in native flora and gold mining waste. The aim of this research is to evaluate the environmental rehabilitation of areas affected by mining by analyzing metal(loid) concentrations in plant and tailing samples from the abandoned Kolar Gold Fields (KGF) in Karnataka, India. Using inductively coupled plasma mass spectrometry (ICP-MS), examined the leaves and twigs of plant samples, as well as soil samples, for specific metal(loid)s: As, Au, Cu, Pb, and Zn. The highest average concentration of gold was found in Eucalyptus globules, with mean values of 5.04 mg/kg in twigs and 6.14 mg/kg in leaves. These findings suggest that this plant species could serve as a model organism for restoring areas affected by gold mining and for investigating the mechanisms behind plant tolerance to heavy metals. Furthermore, since eucalyptus trees may facilitate the movement of gold from mineral deposits, the results support the use of vegetation sampling in mineral exploration as part of biogeochemical studies. These findings suggest that Eucalyptus globulus can be used for phytoremediation in areas impacted by gold mining.