Trace Metals in Selected Fish Species from Five Cowries Creek, Southwest Nigeria: Consumer Safety Assessment

Abstract

This study aims to examine trace metals (Pb, Cd, Cr, Zn, and Cu) concentration in muscle tissues of four fish species from Five Cowries Creek and assess the safety risks posed by consuming these fish species. For this purpose, fish species such as Cynoglossus senegalensis, Mugil cephalus, Chrysichthys nigrodigitatus and Pseudotolithus typus were procured monthly from anglers in Five Cowries Creek, Lagos, from February to May, 2019. The fish muscle tissues were digested according to the international standards, and the trace metals were measured using an atomic absorption spectrophotometer (AAS). Results revealed that the ranking order of trace element concentrations followed this sequence: Pb > Cr > Zn > Cu > Cd. There were significant differences (P < 0.05) in Pb and Cr among the fish species. Consumer health risk was evaluated using non-carcinogenic and carcinogenic risk indices. The results showed that EDI and target hazard quotient (THQ) of Cr, Zn, Cu and Cd suggested that fish species consumption did not pose risk to consumer health. Nevertheless, the estimated daily intake (EDI) along with THQ of Pb indicated potential health risks to consumers (children and adult) of Chrysichthys nigrodigitatus. The target hazard index (THI) of trace elements in all investigated fish species exceeded the guideline value of 1, indicating an adverse health risk for exposed consumers. However, the carcinogenic risk of Pb was negligible for children and adult consumers of fish species. The results are anticipated to create alertness among the public on the safety risks as a result of consuming metal-contaminated fish. Authorised regulatory agencies should control the unregulated uses of Five Cowries Creek, Lagos and associated water bodies through the enforcement of various regulations, policies and laws.