Heavy Metal Contamination Analysis in Sediments of Balu River, Bangladesh

This study assessed heavy metal pollution in sediments of the Balu River, Bangladesh, evaluating contamination levels, ecological risks, and potential sources. Sediment samples were collected from 10 stations along a 4.7 km stretch during wet and dry seasons. Concentrations of zinc, lead, copper, chromium, and cadmium were analyzed. Multiple pollution indices, including geo-accumulation index, contamination factor, and enrichment factor, were calculated. Multivariate statistical analyses were employed to identify pollution sources and spatial patterns. Results revealed significant heavy metal contamination, with zinc and cadmium exhibiting the highest levels of enrichment and ecological risk. Wet season data showed stronger correlations and higher contamination levels, likely due to increased runoff and industrial discharges. Dry season data indicated shifts in dominant pollution sources, with zinc and cadmium showing different associations compared to the wet season. Pollution indices indicated moderate to severe contamination for most metals, particularly cadmium. Statistical analyses suggested industrial activities, vehicular emissions, and urban runoff as primary pollution sources, with distinct spatial patterns identifying contamination hotspots. The findings highlight the critical state of metal pollution in the Balu River, emphasizing the urgent need for targeted pollution control measures and comprehensive environmental management strategies.