Title: Assessment of heavy metals in agricultural and background soils around future copper mine, using enrichment factor and Geoaccumulation index, Iran

Abstract

Heavy metals are pollutants released into different parts of the environment such as soil and plants due to natural and anthropogenic origin. There is a possibility of water, soil, and plant pollution in Darreh Zereshk area in the near future. To assess the soil contamination and determine the origin of selected heavy metals, enrichment factor (EF) and geoaccumulation index (Igeo) were conducted. To aim this purpose a total of 30 agricultural soil samples and 12 background soil samples were collected from Darreh Zereshk area in central Iran which is going to be one of the richest copper mines in Iran and the Middle East. Accordingly, total and soluble concentration of heavy metals (Cu, Pb, Zn, Mn, As, Fe, Ni and Cr) and some Physico-chemical properties of soils were determined. According to the Igeo result Dareh Zeresh village is moderately to heavily contaminated with Cu (2.16), Hasan Abad and Bishe villages are moderately contaminated (1.21, 1.04) and Darreh Gazeh and Dehshir villages are uncontaminated to moderately contaminated (0.01, 0.13), which can be justified by the presence of rich copper deposit in the area and the distances of each village from that. High EF factors for Cu, Zn and especially for Pb as it is not an essential micronutrient, indicate a considerable enrichment caused by pollution. Contamination of the agricultural soils is more severe for Pb, Cu and Zn and less severe for As. The origin of Ni and Cr does not seem to be anthropogenic.