Monitoring Heavy Metal Pollution in the Aras River: A Comprehensive Evaluation Using Pollution Indexes

Heavy metal (HM) pollution may pose a serious risk to aquatic ecosystems. This research sought to determine the content, pollution level, and source of Ni, Pb, Zn, Mn, Cu, Cd, and Fe in Aras River sediments. The bioavailability and contamination of HMs in Aras River sediments were investigated using data from sediment pollution indices, sequential chemical extraction, and the risk assessment code (RAC). The average RAC data revealed that the risk of bioavailability of metals is moderate for Cd, Ni, and Zn, high for Cu, and low for pb. The geoaccumulation index (Igeo) and pollution index (Ipoll) showed that Ni, Pb, Mn, and Zn did not contaminate the sediment, however Cu did. Furthermore, Cd contamination levels in the study region's sediments ranged from moderate to considerable. The cluster and correlation analysis revealed that, whereas natural origins were the predominant sources of Pb and Ni in sediments, Cu, Cd, and Zn came from both natural and human sources. Furthermore, cumulative contamination indicators revealed that Aras River sediment is significantly polluted.