Carcinogenic and Genotoxic Health Risk Assessment Associated with Dietary Exposure to Polycyclic Aromatic Hydrocarbons in Charcoal-Grilled Catfish Consumed in Makurdi Metropolis, Benue State, Nigeria

Abstract

Charcoal-grilled catfish constitutes one of the most widely consumed street and restaurant foods in Makurdi, Benue State, Nigeria, yet the carcinogenic and genotoxic health risks associated with chronic dietary exposure to polycyclic aromatic hydrocarbons (PAHs) in this food commodity have never been quantified for any consumer sub-group in this region. This study evaluated the lifetime carcinogenic risk and hazard quotients (HQ) associated with dietary intake of eight PAH congeners acenaphthene (AC), benzo[a]anthracene (BaA), benzo[b]fluoranthene (Bbf), benzo[k]fluoranthene (Bkf), acenaphthylene (AP), anthracene (A), benzo[ghi]perylene (BghiP), and dibenzo[a,h]anthracene (DBahA) detected in charcoal-grilled Clarias gariepinus, Heterobranchus longifilis, and Heteroclarias (hybrid) from three commercial grilling establishments in Makurdi. The USEPA incremental lifetime cancer risk (ILCR) model and the margin of exposure (MOE) approach recommended by EFSA (2008) were applied, using body-weight-normalised daily intake estimates for adult and child consumer sub-groups based on measured PAH concentrations. DBahA contributed the highest estimated ILCR (adults: 1.13 × 10⁻⁶; children: 3.82 × 10⁻⁶) across all scenarios, followed by BaA (adults: 4.07 × 10⁻⁷; children: 1.38 × 10⁻⁶). Estimated ILCRs for individual congeners fell within the 10⁻⁷ to 10⁻⁶ range for adults and 10⁻⁷ to 10⁻⁵ range for children, indicating a low to borderline acceptable carcinogenic risk level under chronic daily consumption assumptions. Non-carcinogenic hazard quotients for individual PAHs were all below unity for both consumer groups. The MOE for the PAH4 sum exceeded the EFSA threshold of 10,000 for moderate-risk scenarios, indicating that current PAH levels do not constitute an immediate public health emergency. However, the consistent detection of IARC Group 2A carcinogens (BaA, DBahA) and the absence of Nigerian national PAH limits for grilled fish represent critical regulatory gaps requiring urgent attention.