Ecological and Human Health Risks Assessment of Potentially Toxic Elements Contamination of Surface Soils in Shushtar and Dezful, Iran

Abstract

Background: The potentially toxic elements (PTEs) are one of the most dangerous pollutants in the environment. In this study, the elements namely cadmium, lead, chromium, nickel, copper and zinc were investigated in the soil. Methods: In this study, 144 composite samples were randomly prepared from surface soils in a depth of 10 cm in the cities of Shushtar and Dezful. Soil sampling was performed in 12 stations in Shushtar and Dezful. The PTEs were determined by ICP Varian 710-ES device. Results: The pattern of accumulation of PTEs was as Cu>Pb>Cd>Zn>Ni>Cr in Dezful. In Shushtar, the accumulation of metals in the soil was as Cu>Pb>Cd>Ni>Zn>Cr. The concentration of Ni and Cr in the surface soils of Shushtar was higher than Dezful. The Ecological risk of Cd in the surface soils of Dezful and Shushtar was higher than other PTEs. The most important risk factor for carcinogenicity was related to Cr (3.15×10-7) in children. Hazard quotient (HQ) value of studied PTEs for adults and children were obtained by ingestion, inhalation, and dermal contact absorption of less than 1. Conclusion: According to the results, the PTEs of Cd, Pb and Cu caused high pollution in the soils of Shushtar and Dezful, which is due to agricultural, industrial and urban activities in these areas. In general, the metals Cr, Zn and Ni slightly contaminated the soil. Also, the ecological risk of PTEs showed that the highest effects on soil was related to Cd and Pb metals.