Study of the Level of Polycyclic Aromatc Hydrocarbons (PAHs) in Some Locally Smoked Fish Species

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic pollutants which get into foods during processing. In spite of this, only a few studies have been carried out on Nigerian delicacies. This study was used to determine the level of PAHs in some smoked fish species namely: clarias gariepenus (catfish) , scomber scombrus (atlantic mackerel) and clupea harengus (herring fish). The fish species were smoked with a local open-fire fish smoking drum and PAHs were determined using the Gas Chromatography (GC) coupled with flame ionization detector (FID). The levels of PAHs were evaluated on the three species of fish. The total values of PAHs have shown that the smoked clarias gariepenus (catfish) , scomber scombrus (mackerel fish) and clupea harengus (herring fish) have 80.01µg/g, 69.94µg/g and 154.08µg/g respectively. Higher values were found in benzo(a)pyrene and lower values found in naphthalene. For benzo(a)pyrene, the values were 9.20µg/g, 2.90µg/g and 40.13 µg/g respectively. For naphthalene, the values were 1.13µg/g, 1.11µg/g and 1.72µg/g respectively. Benzo(a)pyrene, which is highly carcinogenic was found to have the highest concentration in clupea harengus (herring fish) of about 40.13µg/g which is above permissible level. As for the other PAHs, they were all detected in various quantities which resulted to the high level of the total PAHs in the samples. From the study, it was revealed that the open-fire fish smoking pose a health risk for human as it is being contaminated. It is therefore recommended that a low polycyclic aromatic hydrocarbons (PAHs) improved fish smoking kiln should be developed.