Carcinogenic and non-carcinogenic evaluations of heavy metals in protein foods from southwestern Nigeria

This study evaluated carcinogenic and non-carcinogenic effects of metals in commonly consumed protein food samples collected from three states in Southwestern Nigeria. One hundred and fifty food samples (crayfish, fish, meat and cowskin) were collected and analyzed for Cd, Cu, Cr and Pb using the standard method. Data were evaluated for descriptive and inferential statistics using SPSS for Windows (22.0). The health risk assessments of metals (Cd, Cu, Cr, Pb) were calculated for non-cancer indices (hazard quotient, HQ and hazard index, HI) and cancer risk (CR). Results for Cd varied from 0.85 ± 0.11 mg kg−1in raw fish to 1.20 ± 0.39 mg kg−1in crayfish; Cr from 2.18 ± 0.53 mg kg−1in smoked fish to 2.71 ± 0.32 mg kg−1in crayfish, while Pb ranged from 1.40 ± 0.20 mg kg−1in smoked meat to 2.34 ± 0.62 mg kg−1in cowskin. Cu showed higher significant (p < 0.05) concentration in crayfish (19.92 ± 1.03 mg kg−1) than other protein foodstuffs. The health risk data revealed the average HI values of metals (in raw meat, smoked fish, cowskin and crayfish) greater than 1.0 indicating non-carcinogenic adverse health effects. The data on carcinogenic effects revealed CR values greater than the permissible limit of 1.0 × 10-4 for Cd and Cr indicating cancer risk on consumption of food samples.