Authors: Ikechukwu S. Chikwe, Erienu Obruche Kennedy, Ofogharenor Tanro Maris, Naku Julius Uko, Abubakar Bilyamini Mu’azu, Anyanwu Chidimma Gogo, Omorodion J.I, Michael Asukwo Nseabasi
Abstract: This study evaluated the concentrations of polycyclic aromatic hydrocarbons (PAHs) and selected heavy metals in two commercially important stockfish species, Apama (Sepia species) and Haddock (Melanogrammus aeglefinus), obtained from Onitsha Market, Nigeria, to determine their potential human health implications. Six representative samples collected from different market locations were analyzed using Gas Chromatography–Mass Spectrometry (GC–MS) for PAHs and Atomic Absorption Spectrophotometry (AAS) for heavy metals. Iron was the predominant metal, ranging from 40.28–83.88 mg/kg, followed by zinc (13.00–21.00 mg/kg), copper (0.80–1.90 mg/kg), manganese (3.00–5.99 mg/kg), chromium (≤0.006 mg/kg), lead (ND–0.002 mg/kg), and cadmium (0.00001–0.00020 mg/kg), while nickel, arsenic, and mercury were not detected. The detected concentrations of lead, cadmium, mercury, and arsenic were below the maximum limits recommended by WHO/FAO for fish and fishery products, indicating minimal heavy metal contamination. Sixteen priority PAHs were identified, with phenanthrene, fluoranthene, and pyrene being the most frequently detected compounds. Total PAH concentrations ranged from 0.01034 to 0.23780 µg/kg, whereas benzo(a)pyrene concentrations (ND–0.00020 µg/kg) were far below the European Union maximum limit of 2 µg/kg for smoked fish products. Overall, the analyzed stockfish samples were considered safe for human consumption; however, routine monitoring remains essential to detect future contamination and ensure continued consumer protection.
