Assessment of the metals contamination and their grading by SAW method: a case study in Sarcheshmeh copper complex, Kerman, Iran

Studying the distribution of metals in the soil of mineral regions is one of the most important environmental issues. These metals are transferred to the cycle of nature by geogenic and anthropogenic resources, causing serious short- and long-term effects, and posing serious risks for the survival of living organisms. Various mining activities, smelting and beneficiation processes are important anthropogenic factors in the presence of metals in soil, which play a far more effective role in soil pollution than natural factors. Sarcheshmeh copper mine in Kerman is one of the largest copper sulfide mines in the world, for which evaluation and grading of metals contamination has paramount importance due to the high volume of mining. In this study, in order to determine the metal content in the surface soil from the Sarcheshmeh copper complex soils area, 120 surface soil samples were taken from a depth of 30 cm, and analyzed for the metals Pb, Ni, Se, Mo and Zn using the ICP-MS method. Then, the contamination coefficient, enrichment factor and geoaccumulation index of these metals were calculated. Based on expert views on the relative importance of each of the indicators and their final weight, risk assessment and grading by the simple additive weighting (SAW) method was performed. According to the results, the highest risk of pollution was obtained for nickel and the lowest was for selenium.