Assessment of pollution risks posed by trace elements in the riverbed sediment of the Ganges River in Eastern Uttar Pradesh, India

Abstract

This research investigates trace elements in newly deposited riverbed sediment along a 225-km section of the Ganges River in eastern Uttar Pradesh, India. Samples were collected from 10 locations between Kanpur and Prayagraj, and were analyzed using atomic absorption spectrometry (AAS). The study focused on eight heavy metals: iron (Fe), manganese (Mn), cadmium (Cd), copper (Cu), chromium (Cr), nickel (Ni), lead (Pb), and zinc (Zn). The pollution risk was assessed using four indicators: enrichment factor (EF), Geo-Accumulation Index (GAI), contamination factor (CF), and Pollution Load Index (PLI). Fe (24,288 ppm) had the highest average concentration, followed by Mn (488.9 ppm), Cr (52.36 ppm), Zn (29.75 ppm), Ni (29.71 ppm), Pb (23.36 ppm), Cu (22.95 ppm), and Cd (1.10 ppm). Average values of CF indicated moderate contamination by Pb (1.06) and Cd (1.89). The average EF values for Cd at 3.15 showed moderate enrichment (EF between 2 and 5). GAI values indicated “uncontaminated to moderate” contamination (GAI between 0 and 1) by Cd (0.30), posing potential ecological risks. PLI values suggested baseline sediment contamination (PLI < 1) across all sites. The study highlights that Cd and Pb levels are concerning and may worsen with increased human activity in the river's catchment area.