Nutritional–Toxicological Trade-Off: Comparative Study of Polycyclic Aromatic Hydrocarbons in Smoked and Oven-Dried Nile Tilapia (<i>Oreochromis niloticus</i>)

Polycyclic aromatic hydrocarbons (PAHs) are environmental contaminants of major toxicological concern due to their mutagenic and carcinogenic effects. This study assessed PAH contamination and proximate composition in Nile tilapia (Oreochromis niloticus) processed using four methods: air drying (FAD), oven drying (FOD), firewood drying (FWD), and firewood + polythene drying (FWP). Proximate composition was determined by AOAC methods, while PAHs were extracted by Soxhlet, purified with silica gel chromatography, and quantified using gas chromatography mass spectrometry (GC–MS). Of the 24 priority PAHs in the calibration standard, 12 were detected, with naphthalene being dominant (54.22–112.85 mg/kg). Low molecular weight (LMW) PAHs accounted for more than 95% of total contamination, but high molecular weight (HMW) PAHs of greater carcinogenic significance including chrysene, benzo[b,j,k]fluoranthene, 3-methylcholanthrene, and dibenzopyrenes were present in smoked fish. Proximate analysis confirmed high protein (56–59%) and lipid (14–15%) content across all treatments, though FWP samples showed reduced protein quality. Regulatory comparison showed that PAH4 concentrations exceeded European Union safety limits. In FWP samples, levels were up to 37 times higher than the permissible threshold. Toxic equivalency analysis further estimated a benzo[a]pyrene equivalent burden of 0.536 mg/kg in polythene-smoked fish. These findings highlight a nutritional–toxicological trade-off: while fish remains a vital protein source, traditional smoking especially with polythene introduces unacceptable PAH levels. Oven drying preserved nutrient quality while minimizing PAHs and is recommended as a safer alternative. The study emphasizes the need for consumer education, improved smoking technologies, and regulatory enforcement to reduce dietary exposure to carcinogenic PAHs.