EXPLORATORY HEALTH RISK ASSESSMENT OF ESSENTIAL AND NON- ESSENTIAL TRACE ELEMENTS IN CAGE-CULTURED FISH SPECIES FROM BADAGRY LAGOON, NIGERIA

Abstract

Fish readily accumulate trace elements from water, sediments, and feed, making them potential vectors of human exposure. This study assessed the concentrations, estimated daily intake (EDI), and potential health risks of essential and non-essential trace elements in water, sediment, and two cage-cultured fish species—Clarias gariepinus and Oreochromis niloticus—from Badagry Lagoon, Nigeria, using standard methods. Results revealed that sediments consistently contained significantly higher concentrations (P < 0.05) of all trace elements, underscoring their role as primary sinks for metal pollutants. Among the fish species, C. gariepinus exhibited higher accumulation of copper, manganese, and zinc, while O. niloticus showed elevated levels of silver, tin, and cadmium. Zinc was the most abundant essential element in both sediment and fish tissues, while mercury levels remained uniformly low across both species. EDI values for all analysed elements were well below oral reference doses, indicating no immediate dietary health risks. Furthermore, Target Hazard Quotient (THQ) values for both essential and non-essential elements in both fish species were below the critical threshold of 1, suggesting negligible non-carcinogenic risk. However, significant interspecies differences in THQ values for several elements imply species-specific bioaccumulation tendencies. The findings highlight the importance of continuous environmental monitoring and species-specific risk assessments to ensure the nutritional safety of fish from aquaculture systems in urbanized lagoon environments.