Trace Element Bioaccumulation in Commercial Nile Tilapia from Brazil: Screening-Level Assessment and Food Safety Implications

This study evaluated trace element bioaccumulation in Nile tilapia (Oreochromis niloticus) marketed in Brazil and assessed potential implications for food safety and human health. A total of 120 farmed fish samples, including whole fish and tissues (gills, kidneys, liver, and muscle), were analyzed. Concentrations of Al, As, Cr, Cu, Fe, Mn, Ni, Pb, Se, and Zn were determined by inductively coupled plasma optical emission spectrometry (ICP-OES) and compared with ANVISA and FAO/WHO guideline values. Arsenic concentrations complied with ANVISA limits, whereas Pb in whole Nile tilapia exceeded the permissible threshold. Nickel and Se concentrations in muscle and whole fish also surpassed FAO/WHO guidelines. Estimated Se intake from consumption of whole tilapia and muscle (fillet) reached 188.01% of the Recommended Dietary Allowance (RDA) for children aged 8 years. Contamination index values (CI) indicated bioaccumulation of Ni in multiple tissues and Se in edible portions. Human health risk assessment identified carcinogenic risks associated with As, Cr, Ni, and Pb, while non-carcinogenic risk (HI > 1) was primarily driven by As exposure. These findings highlight the need for continuous monitoring of trace elements in aquaculture products.