Ecological and human health risks of potentially toxic elements across land uses in a dust-prone region of Central Iran

This study examined the ecological and human health risks related to potentially toxic elements (PTEs) in soils across five different land uses in a dust-prone area of central Iran. In total, 107 surface soil samples and 32 subsurface samples were collected from industrial areas, agricultural lands, rangelands, barren areas, and planted forests. The concentrations of Arsenic (As), Cadmium (Cd), Lead (Pb), Nickel (Ni), Chromium (Cr), Zinc (Zn), Copper (Cu), and Vanadium (V) were measured, and ecological and health risks were assessed using the improved weighted index (IWI), hazard index (HI), and total cancer risk (TCR). The highest mean concentrations (mg/kg) of PTEs were observed in planted forests (As: 8.72; Cd: 0.45), industrial lands (Cd: 0.45; Cr: 18.3; Ni: 22.18; V: 32.83), and rangelands (As: 9.9; Cd: 0.45; Cu: 15.15; Pb: 12.45). Based on IWI, 33%, 47%, and 20% of soil samples were classified as unpolluted, low, and moderately polluted, respectively. The HI values for both adults and children were < 1, indicating no non-carcinogenic risk, while TCR values indicated potential carcinogenic risk, with the highest and lowest values in industrial areas (1.68 × 10⁻⁴) and agricultural lands (1.50 × 10⁻⁴), respectively. Sensitivity analysis showed that As in the planted forest had the highest contribution to the non-carcinogenic risk for adults and children, and Pb in rangelands had the highest contribution to the total carcinogenic risk. Since the study area is one of the areas prone to dust storms, the presence of PTEs, especially Cr, As, and Ni, may be pose additional risks to residents of these areas. Thus, regular monitoring of these pollutants in the soil of planted forests and appropriate management is recommended to reduce environmental and health risks.