Analytical Investigation of Polycyclic Aromatic Hydrocarbon Contamination in Smoked Fish Sold in Markets across South South Nigeria

Traditional fish smoking using wood fuel is the dominant fish preservation method across the South South geopolitical zone of Nigeria, and the resulting polycyclic aromatic hydrocarbon contamination in smoked fish products constitutes a documented food safety and cancer risk concern. This study analytically investigates polycyclic aromatic hydrocarbon profiles in smoked fish samples collected from markets in Port Harcourt, Uyo, Warri, Calabar, Asaba, and Yenagoa, representing all six states of the South South zone. Smoked mackerel, catfish, and tilapia samples were collected from five vendors per city, extracted by saponification and liquid-liquid extraction, and purified by silica gel column chromatography before analysis by gas chromatography-mass spectrometry. The fifteen EU priority polycyclic aromatic hydrocarbons were quantified and benchmarked against European Food Safety Authority maximum limits and WHO dietary exposure guidelines. Total polycyclic aromatic hydrocarbon concentrations ranged from 18.4 to 146.7 micrograms per kilogram depending on fish species, smoking method, and fuel type. Benzo(a)pyrene, the EU marker polycyclic aromatic hydrocarbon for smoked food, exceeded the maximum limit of 2.0 micrograms per kilogram in 43.3% of samples. Catfish smoked using sawdust-fired drum kilns recorded the highest concentrations. Incremental lifetime cancer risk estimates based on dietary intake data indicated elevated cancer risk for heavy smoked fish consumers in the South South zone. The study provides actionable data for Nigerian food safety regulations on smoked fish and supports the adoption of clean smoking technologies. Keywords: polycyclic aromatic hydrocarbons, smoked fish, GC-MS, cancer risk, South South Nigeria