Abstract

Background: The present study aims to assess the amounts of Zn, Cu, Cd, Pb, Ni, Co, Mn, and Fe by analyzing the particle composition of the surficial sediments in Ghezel Ozan River located in Zanjan, Iran. Methods: 18 sediment samples were collected from Ghezel Ozan River. After Aqua Regia Digestion, the studied heavy metals in sediment samples were determined by flame atomic absorption spectrophotometry. Several pollution indices, such as Enrichment Factor (EF), Geo-accumulation Index (I_geo), Pollution Factor (C_d), and Pollution Load Index (PLI), were calculated. Results: Observed average values (in unit mg kg⁻¹) were in the range of Zn: 480.0-34294.0, Cu: 7.8-32.00, Cd: not detected -100.0, Pb: 22.0-256.0, Ni: 2.50-60.00, Co: 7.60-34.0, Mn: 144.0-31600.0 and Fe: 9320.0-62300.0. The I_geo index confirmed that the average values of Zn, Pb, and Cd are in the heavily contaminated levels. The mean EF index suggested minimal enrichment for Cu, Ni, Mn, and Co, whereas Zn, Cd, and Pb indicated severe enrichment. Conclusion: The average C_d, RI, and PLI indices for all investigated heavy metals confirmed a considerable contamination level.