Quantitative Occurrence of Polycyclic Aromatic Hydrocarbons in Heat-Processed Fish and Meat Products in Variable Processing Matrices

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic contaminants formed endogenously during high-temperature processing of protein-rich foods. This investigation evaluated the occurrence and dietary risk associated with four priority PAHs — benzo[a]pyrene (BaP), chrysene (Chr), benz[a]anthracene (BaA) and benzo[b]fluoranthene (BbF), collectively termed PAH4 — in traditionally processed fish and meat foods sampled from markets across six geopolitical zones of Nigeria. A total of 60 samples comprising smoked catfish, smoked tilapia, smoked mackerel, suya, kilishi and balangu were collected and analysed by high-performance liquid chromatography with fluorescence detection (HPLC-FLD) following solid-phase extraction (SPE) clean-up. BaP concentrations ranged from 0.4 to 33.9 µg/kg across matrices, with smoked mackerel from Rivers State recording the highest mean value (12.1 ± 3.4 µg/kg). Traditional Nigerian grilled meat products exhibited markedly lower but still concerning PAH4 concentrations. Kilishi recorded higher BaP levels (5.1 µg/kg) than suya (6.2 µg/kg) while balangu showed lowest BaP value (4.7±1.5µg/kg). The EU regulatory maximum of 2 µg/kg was exceeded in 74.2% of smoked fish samples and 41.8% of grilled meat samples. In total PAH4, Rivers State recorded the highest mean PAH4 concentrations (44.2 µg/kg), Cross River State also demonstrated elevated contamination levels (41.7 µg/kg). In contrast, the FCT Abuja recorded comparatively lower levels (22.1 µg/kg). PAH4 sum exceeded 12 µg/kg in 68.4% of smoked fish products. In the case of fuel type, Rubber wood and sawdust frequently used by artisanal processors because of their low cost and wide availability generated PAH4 concentrations 2.3–2.9 fold higher than hardwood iroko and 2.9–3.7 fold higher than coconut shell charcoal. Significant correlations were found between PAH4 burden and fuel type (H = 41.3, p < 0.001), fat content (r = 0.98, p < 0.001) and processing temperature (r = 0.94, p < 0.001). These data underline an urgent need for harmonised Nigerian food safety regulations governing PAH limits in thermally processed protein foods, improved traditional smoking technologies, and targeted consumer risk education.