Heavy metals contamination: possible health risk assessment in highly consumed fish species and water of Karnafuli River Estuary, Bangladesh

Objective We have analyzed the heavy-metal contamination in highly consumed fish species and water collected from the Karnafuli River estuary and assessed the possible health risks. Materials and Methods Eight fish species and three water samples were collected for winter and summer from the Neval region, Karnafuli and Kalurghat bridge. The heavy metals (HMs) concentrations were measured for edible, inedible parts of fish and water samples using Flame Atomic Absorption Spectroscopy and Graphite Furnace Atomic Absorption Spectroscopy. Results Among the studied fish samples, the highest accumulation was found in Apocryptes bato where the lowest accumulation was found in Setipinna phasa & Setipinna taty. The order of mean accumulation in fish samples was Fe > Zn > Mn > Cu > Cr > Cd > Pb > As. The contents of Fe, Zn, Mn and Cr were significantly higher than the permissible limits. The bioaccumulation of HMs in inedible parts (summer) was higher than that of edible parts (winter). The concentration of HMs for water samples follows a decreasing trend: Neval region > Kalurghat bridge > Karnafuli bridge. The average concentration of essential HMs in water samples was Fe > Mn > Cr > Cu > As. Hazard quotient (HQ) and hazard index (HI) are < 1 for all fishes and > 1 for water samples. Resembling, target cancer risk (TR) lies within E-07 to E-04 for fishes but TR > E-4 for Cr in water samples. Health risk assessment for fishes always lies within the acceptable limit referred by WHO/FAO but over for water; indicates adverse health impacts via ingestion of polluted water. Conclusion Results anticipated that there are risks for human health and fatal diseases due to immuno-toxicological effects by continuous uptake of these contaminated fishes and water and require regular monitoring to reduce pollution.