Heavy metals accumulation in some important fish species cultured in commercial fish farm of Natore, Bangladesh and possible health risk evaluation

Heavy metal contamination in aquatic environment is a serious concern throughout the world. Metal contamination are responsible for the accumulation of metals within the fish body. And, consumption of these contaminated fish possess serious threat to the associated consumers. In this current study, five commonly cultured freshwater fishes (rui, Labeo rohita; mrigal, Cirrhinus mrigala; silver carp, Hypophthalmicthys molitrix; bata, Labeo bata, and sarpunti, Puntius sarana) were collected from a commercial fish farm of Natore district, Bangladesh to analyze metals levels in edible portion (flesh), and to assess the associated human health risk. Several heavy metals such as zinc (Zn); cadmium (Cd); chromium (Cr); arsenic (As); lead (Pb); and nickel (Ni) were analyzed by a flame atomic absorption spectrophotometer. Besides, the target hazard quotient (THQ), hazard index (HI) and lifetime cancer risk (TR) were also estimated for assessing the associated human health risk. In this study, concentrations of Zn, Cd, Cr, As, Pb and Ni in different fish species were found 6.36 ± 1.48 to 13.31 ± 1.33; 0.017 ± 0.01 to 0.049 ± 0.02; 0.654 ± 0.04; 0.015 ± 0.01 to 0.033 ± 0.01; 0.534 ± 0.11 and 0.08 ± 0.05, respectively. All the analyzed values were within the recommended level except Cr in C. mrigala. The THQ, HI and TR values of all the analyzed metals in the fishes indicated that no associated cancer risk resulting from the consumption of those fishes. Therefore, the current study revealed that fishes of the target area might be free from associated metals contamination and hence, might be safe for human consumption.