POLYCYCLIC AROMATIC HYDROCARBONS CONTENT IN SMOKED FISH AND MEAT PRODUCTS FROM NORTH-CENTRAL AND NORTH-EASTERN NIGERIA

The study determined polycyclic aromatic hydrocarbons (PAHs) in fish, beef and cowhides collected from processors in parts of North Central and North Eastern Nigeria before and after contact with smoke. It also determined concentrations of PAH in the smoked products contributed from smoke. Samples were extracted in a sonicator using a mixture of dichloromethane and hexane then cleaned up with the same solvents in a column before analysis with a gas chromatograph fitted with flame ionization detector. The results revealed that the total mean PAH concentrations (µgkg-1) in the samples before contact with smoke were 5.6752 (fish) > 2.1602 (cowhide) > 0.4363(beef). After contact with smoke however, the mean total concentrations (µgkg-1) of the PAHs were 20.1520 (smoked dried fish) > 17.6586 (smoked semi-dry fish) > 2.7370 (smoked cowhide) > 1.2519 (smoked beef). The study further revealed that higher concentrations of PAH4 (benzo[a]pyrene, benz[a]anthracene, benzo[b]fluoranthene and chrysene) in the fish and beef were contributed from the smoke. In the smoked semi-dried fish (SSF), the concentrations (µgkg-1) from the smoke relative to other environmental sources were 0.1464, 0.0132 (benz[a]anthracene), 0.0722, 0.0112 (chrysene) 0.0147, 0.0050 (benzo[b]fluoranthene) and 0.1397, 0.0407 (benzo[a]pyrene). The smoked dried fish had their concentrations (µgkg-1) to be 0.1828, 0.0132 (benz[a]anthracene), 0.0362, 0.0112 (chrysene), 0.0182, 0.0050 (benzo[b]fluoranthene) and 0.1595, 0.0407 (benzo[a]pyrene). Concentrations in the smoked beef were 0.0025, 0.0070 (benz[a]anthracene), 0.0134, 0.0120 (chrysene), 0.0016, 0.0014 (benzo[b]fluoranthene) and 0.3603, 0.1216 (benzo[a]pyrene). The PAH4 concentrations in the cow hide contributed from the smoke were either low or not present at all. This concentrations were corroborated with the % PAH contamination level developed from the study. The % PAH contamination levels were in the ranges of 32-94 (smoked semi-dried fish), 33-95(smoked dried fish), 0-89 (smoked beef) and 0-94 (smoked cowhide). Generally, benzo[a]pyrene and most of the PAHs were significantly greater in the smoked products than the non smoked ones. However, benzo[a]pyrene concentration and sum of PAH4 fell below the Food Standard Agency acceptable limits of 2 µgkg-1 and 12 µgkg-1 respectively. The research has contributed to the database of polycyclic aromatic hydrocarbon concentrations in North Central and North Eastern Nigeria. Based on the data generated, the study thus proposes a standard of 1 µgkg-1and 5 µgkg-1 for benzo[a]pyrene and ∑PAH4 in smoked fish and meat products in Nigeria.