Metal Contamination in Blue Foods and Human Health Risk

Blue foods, including fish, shellfish, and other aquatic organisms, are important for global food security, providing high-quality protein, omega-3 fatty acids, vitamins, and minerals while supporting the livelihoods of millions of people. However, increasing industrialization, urbanization, agricultural runoff, mining activities, and poor waste management have led to the release of toxic metals into aquatic ecosystems. Metals such as mercury, lead, cadmium, arsenic, and chromium can accumulate in sediments and aquatic organisms through bioaccumulation, eventually entering the human food chain through seafood consumption. Exposure to elevated concentrations of these metals has been linked to adverse health effects, including neurological disorders, kidney and liver damage, cardiovascular diseases, developmental abnormalities, and cancer, raising concerns about the safety and sustainability of blue foods. The aim of the study was to determine accumulation of heavy metals in selected commercial fish species: Leptoscarus vaigiensis, Lethrinus harak, L. mahsena, L. microdon, L. obsoletus, Lutjanus fulviflamma, and Siganus sutor and potential human health risks associated with their consumption in South Coast, Kenya. Health risks were assessed using Estimated Daily Intake (EDI), Target Hazard Quotient (THQ), Hazard Index (HI), and Carcinogenic Risk (CR) models. Results revealed species-specific differences in metal-related health risks. Adult THQ values ranged from 0.002 to 2.31, whereas children showed higher values ranging from 0.005 to 5.39. Similarly, HI values were higher in children (4.98–10.91) than in adults (2.13–4.68), indicating greater susceptibility. Carcinogenic risk values also followed the same trend, with adults ranging from 5.6 × 10⁻⁴ to 1.17 × 10⁻³ and children from 1.31 × 10⁻³ to 2.73 × 10⁻³.These findings highlight the potential health risks associated with consuming metal-contaminated fish, particularly among children, and emphasize the need for continuous monitoring, effective pollution control, and stronger regulatory measures to ensure seafood safety and protect public health.