Non-carcinogenic and Carcinogenic Health Risk Evaluation from Fish Contaminated with Heavy Metals

Abstract

The pollution of water bodies with heavy metals can result into the possible contamination of freshwater fish. The levels of the heavy metals Pb, Fe, Cu, Zn, Ni and Cd were investigated in fish samples (Ameiurus nebulosus, Pylidictis olivaris, Tilapia zilli, Clarias gariepinus) collected from Kwanar-Are dam located at Rimi local government area Katsina State, Nigeria and the health risks of the evaluated heavy metals were estimated.  The mean concentration ranges of Pb, Fe, Cu, Zn and Cd were (0.0851-0.4919, 0.3095-0.5039, 0.0366-0.0589, 0.1066-0.3015, 0.1048-0.1417, 0.0128-0.0686 mg/kg) respectively. The risk assessment for non-carcinogenic exposure effect showed that there was no health risk associated with these elements through consumption of the fish samples to the consumer population. However the risk assessment for carcinogenic exposure effect has revealed that the incremental lifetime cancer risk (ILCR) and the cumulative lifetime cancer risks (∑ILCR) were all above the safe limit for cancer in the children and the adults population for all the fish samples evaluated. The heavy metal Ni presented the greatest cancer risk and the fish sample Clarias gariepinus having the highest cancer risk. There is a degree of concern for consumption of the fish samples for their potentials to contribute to the population cancer risk load.