Evaluation of Heavy Metals in Gadus morhua and the Associated Cancer Risks

Gadus morhua is a good protein source but some methods of its preservation can be a source of heavy metals contamination. Gadus morhua samples were collected from nine major markets for the identification and quantification of heavy metals. An Atomic Absorption Spectrophotometer (AAS) from an analytical and consultancy laboratory in the Department of Soil Resources Management, University of Ibadan was used for the heavy metal analysis after digesting the sample. The mean level of concentrations of the carcinogenic metals (Cd, Cr, Co, Pb, As, and Ni) identified are 0.110, 0.217, 0.440, 0.716, 0.574, and 0.284 mg/kg respectively, while for non-carcinogenic metals; Mn, Zn, Fe, and Cu the mean concentrations are 0.267, 0.636, 0.024 and 0.937 mg/kg respectively. Health risks for both adults and children were examined, which revealed that the risks for adults are greater than those for children. Also, the lifetime cancer risk was found to be higher than the recommended lifetime cancer risk. The mean level of concentrations of, Zn, Fe, Cu, Cd, Co, and As were lower than the recommended values; Ni is the same as the recommended value while the mean concentrations of Mn, Cr, and Pb are higher than their respective safe limits. The high concentrations of the carcinogenic metals Cr and Pb in Gadus morhua indicate therefore that consumption of Gadus morhua poses health risks to the public.