Heavy Metals Contamination in Water, Soil, and Fishes of Bangshi River (Bangladesh): A Growing Threat to Aquatic Life and Human Health

Background: Heavy metal pollution is a growing global concern, intensified by rapid industrialization, urbanization, and poor waste management, particularly in least developed countries like Bangladesh. The Bangshi River in Savar, Dhaka, is heavily polluted with industrial effluents, untreated sewage, and solid waste. Objectives: This study aimed to assess heavy metal contamination in the river’s water, soil, and native fish species. Methods: All three samples were collected from three contaminated sites of Bangshi river. Water and soil were both collected during wet and dry season. Fish species were collected during wet season only. Quantitative analysis of heavy metals was performed by atomic absorption spectroscopy. Results: Our study found that the amount of Cadmium (Cd), Chromium (Cr), and Lead (Pb) were elevated in the soil and water of the river. Notably, Cd and Pb levels in Colisa fasciatus were four and two times higher than permissible limits, with a nine-fold of Cd accumulation in the fish’s head. The average concentration of Cd in Heteropneustes fossilis fish was three times higher than the maximum permissible limit. We also found that the concentration of Cd in Mystus vittatus fish was six times higher, exceeding the maximum permissible limit of Cd in fishes. The concentrations of Cadmium, Chromium, Lead, Zinc, Copper, Iron, and Manganese in other examined fishes were within the permissible limits or slightly increased. Conclusion: Our results reveal heavy metal pollution in the Bangshi River, calling for immediate monitoring and prompt action to protect both the environment and human health.