Bioaccumulation of Cadmium and Lead in Commercially Available Fish in Kaduna North, Nigeria

This study investigated the levels of cadmium (Cd) and lead (Pb) in commercially available frozen, smoked, and canned fish in Kaduna North, Nigeria, and explored the relationship between heavy metal contamination and the presence of Listeria species. Atomic absorption spectrophotometry was used to determine Cd and Pb concentrations. Results showed that mean Cd levels in all fish types exceeded the European Union's maximum residue limit (MRL) of 0.05 µg/g, with smoked fish exhibiting the highest concentrations. Similarly, a significant Proportion of fish samples surpassed the EU's MRL for Pb (0.02 µg/g), particularly smoked and canned fish. Pearson's correlation analysis revealed a strong positive correlation between Listeria occurrence and Cd levels, as well as notable correlations between Listeria and Pb, and between Cd and Pb. These findings highlight significant heavy metal contamination in fish, posing a substantial public health risk. The correlations suggest a potential link between heavy metal presence and Listeria proliferation, emphasizing the need for stringent monitoring and regulatory measures to ensure seafood safety.