Abstract

• Severe heavy metal contamination in freshwater ecosystems and significant health risks can result from mining activities. The current study aimed to assess the seasonal variations of heavy metal concentrations (lead, cadmium, arsenic and mercury) in fishes (Wallago attu and Cirrhinus mrigala) and their environs (water and sediment), Chindwin River segment, Homalin Township, Sagaing Region. The analysis was conducted using a Flame Atomic Absorption Spectrometer at the Universities’ Research Centre of the University of Yangon and the Water Quality Laboratory in Yezin, Nay Pyi Taw. The study spanned from December 2022 to November 2023. Heavy metal concentrations were found to vary depending on the seasons (hot, rainy and cold) and species. The highest concentrations of Pb were recorded in both Wallago attu and Cirrhinus mrigala during the hot season. However, the concentrations of As, Hg, and Cd in the studied fish species were recorded within the maximum permissible limits set by the World Health Organization/Food and Agriculture Organization (WHO/FAO). These findings suggest that the fish, water and sediments in the study area may not be entirely safe from toxic metal contamination. The observed values for all tested metal concentrations of studied fish species and their environments, except for water, were below the maximum permissible limits, indicating a relatively lower risk of contamination.