Metal and metalloid accumulation in native plants around a copper mine site: implications for phytostabilization

Abstract

Mining activities can result in a pollution legacy of metal and metalloid containing soils and wastes. In this study concentrations of the metals and metalloids Al, As, Ca, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pb, Zn, and the non-metals (P, S) were measured in the shoots of 35 different plant species spontaneously growing at four contaminated sites around the Sungun Copper Mine in East Azerbaijan (Iran) in order to evaluate their potential in phytoremediation of this area. The results show that metal and metalloid accumulation differed between the different species. None of the plant species exceeded the relevant trace element hyperaccumulation thresholds. Plant accumulation of Al was found to be relatively high in Achillea vermicularis (Asteraceae, with up to 5,280 μg g⁻¹) and in Trifolium fragiferum (Fabaceae, with up to 4,895 µg g⁻¹). Papaver dubium (Papaveraceae) had relatively high foliar Cu concentrations (with up to 294 µg g⁻¹) while growing in the waste Rrock dump. Teucrium polium (Lamiaceae) had the highest concentrations of Pb (with up to 62 µg g⁻¹). Most of the native species can be classed as metal-tolerant “excluder”-type species, and may, therefore, be suitable for phytostabilization of the mining wastes around the Sungun Copper Mine.

Novelty statement

Plants growing on metalliferous soils are threatened by mining and mineral extraction. Identifying the flora in metal-contaminated soils and mineral wastes is of great importance for biodiversity conservation and for their use in future reclamation programs. This study adds valuable information on the potential of native plants for use in the phytoremediation of copper mines in Iran, as well as in other parts of the world with a similar geology and climate.

Keywords:

• Excluders
• metallophytes
• phytostabilization
• remediation
• trace elements

Acknowledgments

Special thanks go to Nader Mazaheri, Esmat Esmaielzadeh, and Reza Naseh from NICICO for their support during the fieldwork.

Disclosure statement

The authors declare that they have no competing interests.

Additional information

Funding

The present work was financially supported by the Sari Agricultural Sciences and Natural Resources University (SANRU) and National Iranian Copper Industries Company (NICICO).