Distribution of potentially toxic elements (PTEs) in tailings, soils, and plants around Gol-E-Gohar iron mine, a case study in Iran

This study investigated the concentration of potentially toxic elements (PTEs) including Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, V, and Zn in 102 soils (in the Near and Far areas of the mine), 7 tailings, and 60 plant samples (shoots and roots of Artemisia sieberi and Zygophylum species) collected at the Gol-E-Gohar iron ore mine in Iran. The elemental concentrations in tailings and soil samples (in Near and Far areas) varied between 7.4 and 35.8 mg kg⁻¹ for As (with a mean of 25.39 mg kg⁻¹ for tailings), 7.9 and 261.5 mg kg⁻¹ (mean 189.83 mg kg⁻¹ for tailings) for Co, 17.7 and 885.03 mg kg⁻¹ (mean 472.77 mg kg⁻¹ for tailings) for Cu, 12,500 and 400,000 mg kg⁻¹ (mean 120,642.86 mg kg⁻¹ for tailings) for Fe, and 28.1 and 278.1 mg kg⁻¹ (mean 150.29 mg kg⁻¹ for tailings) for Ni. A number of physicochemical parameters and pollution index for soils were determined around the mine. Sequential extractions of tailings and soil samples indicated that Fe, Cr, and Co were the least mobile and that Mn, Zn, Cu, and As were potentially available for plants uptake. Similar to soil, the concentration of Al, As, Co, Cr, Cu, Fe, Mn, Mo, Ni, and Zn in plant samples decreased with the distance from the mining/processing areas. Data on plants showed that metal concentrations in shoots usually exceeded those in roots and varied significantly between the two investigated species (Artemisia sieberi > Zygophylum). All the reported results suggest that the soil and plants near the iron ore mine are contaminated with PTEs and that they can be potentially dispersed in the environment via aerosol transport and deposition.