Mapping of Fuel Wood Types Used in Smoking Fish in Relation to Occurrence of PAHs in Smoked Fish in Nigeria

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are organic contaminants present in fuel woods which are hazardous to human health. The aim of the study is to determine the level of PAHs present in fuel woods used for smoking fish in Nigeria. Samples of fuels collected all over Nigeria were categorized into Hard, Soft and Starters. Four samples were extracted and analyzed using gas chromatography attached with a mass spectrophotometer. The result showed that all the fuelwoods have PAHs below maximum permissible level. Teak wood has high level of PAHs in Naphthalene 0.048 ± 0.000132, Acenaphthylene 0.0013 ± 0.00005, Fluorene 0.0105 ± SE-05, Pyrene 0.0105 ± SE-05, Fluoranthene 0.0119 ± 0.0001, Triphenylene 0.0011 ± 1E-04, Benz(a)anthrax 0.0008 ± SE-05. The order of increase of hazard (PAHs) for the fuel woods are Tectona spp > Azadirachta spp > Mangifera spp > Anacardium spp. When the four fuel woods were used to smoke the same fresh Clarias gariepinus with the same equipment, it was revealed that all were having a high level of PAHs above maximum permissible limit. Fish smoked with Anacardium spp of wood has the highest level of PAHs. Therefore, excess use of Anacardium spp of woods should be averted when smoking fish because of the lipophilic nature of PAHs.