Concentrations and profiles of polycyclic aromatic hydrocarbons in some popular fish species in Nigeria.

The concentrations and profiles of polycyclic aromatic hydrocarbons (PAHs) in 10 popular fish species in the Nigerian market were determined with a view to providing information on the health hazards associated with the consumption of these fish species. The concentrations of PAHs were measured by gas chromatography-mass spectrometry after extraction by ultrasonication with acetone-dichloromethane and clean up. The concentration ranges of the Σ16 PAHs were 20 to 39.6 μg kg(-1) for Parachanna obscura (African snake head), 6.8 to 532.3 μg kg(-1) for Oreochromis niloticus (tilapia), 7.4 to 91.1 μg kg(-1) for Gymnarchus niloticus (Asa), 13.1 to 34.1 μg kg(-1) for Sebastes fasciatus (red fish), 11.2 to 80.0 μg kg(-1) for Gadus morhua (cod), 23.9 to 34.6 μg kg(-1) for Chrysicthys nigrodigitatus (silver cat fish), 63.4 to 131.4 μg kg(-1) for Sardinella aurita (sardine), 22 to 52.9 μg kg(-1) for Trachurus trachurus (Atlantic horse mackerel), 21.0 to 63.7 μg kg(-1) for Scomber scombrus (mackerel), and 27.7 to 44.5 μg kg(-1) for Pseudotolithus senegalensis (croaker). Benzo[a]pyrene occurred in 23% of these fish samples at concentrations above the European Union permissible limit of 2.0 μg kg(-1). The calculated margins of exposure based on the indicators for occurrence and effects of PAHs were greater than 10,000 indicating no potential risk for the consumers of the species evaluated in this study.