Evaluation of PAH Contamination from Smoke in Smoked Fish Obtained from Northern Nigeria

Atlantic mackerel (Scomber Scombrus) fish were collected from processors in parts of northern Nigeria.The PAHs in smoked and non smoked samples were extracted with a mixture of dichloromethane and hexane in the ratio of 3:1 then cleaned up in a column packed with alumina.The cleaned extract was analyzed with gas chromatograph (HP 6890) coupled to flame ionization detector (FID).The study revealed that the total PAH concentrations in the non smoked fish is 5.675µgkg -1 while the total PAH concentrationsin the smoked fishes were 17.965 µgkg -1 (smoked semidried fish) and 20.150 µgkg -1 (smoked dried fish) respectively.The % PAH contamination levels from smoke in the smoked semi-dried fish was in the range of 20-94 while that for the smoked dried fish was in the range of 20-95.Indeno[1,2,3-cd]pyrene had the lowest contaminations from smoke in both the smoked semi-dried and smoked dried fish.Twelve of the sixteen listed USEPA PAHs had mean concentrations that were statistically significant between the smoked fish and non smoked fish (p<0.05).However, acenaphtylene, benz[a]anthracene, dibenz[a,h]anthraceneand indeno[1,2,3cd]pyrene which contaminated the fish were not significant statistically (p>0.05).Generally, the smoked dried fish were more contaminated than the smoked semi-dried fish.Nevertheless, the smoked fish were within the recommended Food Standard Agency limits of 2 µgkg -1 and 12µgkg -1 for benzo[a]pyrene and PAH4 respectively.Consumption of small quantities of smoked fish may not necessarily pose threat to health.The study also provided database on PAH in foods fromparts of northern Nigeria which could contribute to establishing Nigerian standards for PAH in foods.