Polycyclic aromatic hydrocarbons (PAHs) are persistent environmental pollutants known to be carcinogenic, mutagenic and teratogenic to humans and other organisms. These PAHs enter the environment by combustion and fossil fuel sources and can enter food chain through plant up take from contaminated soils. In this study, PAHs contamination levels of locally produced grains in Nigeria have been assessed. Samples of various types of grains which were rice, beans, maize, guinea corn, wheat, soya beans, pigeon pea, bambara nut were purchased from various markets in Eastern Nigeria. The gram samples were extracted by sonication. The concentration levels of sixteen priority PAHs in the grains were determined using gas chromatography coupled with flame ionization detector, GC-FID. The average PAHs concentrations ( × 10-2 µg/kg ) in various rice samples ranged from 0.04 to 4.68, from 0.03 to 5.27 in maize, 0.03 to 5.64 in wheat, 0.02 to 6.55 in guinea corn, 0.03 to 4.75 in beans, 0.06 to 4.46 in soya beans, 0.03 to 5.91 in pigeon peas and 0.02 to 6.31 in bambara nut. The PAHs were wide spread being determined in all the grains. Benzo[a]pyrene showed the highest concentration in all the analyzed grains at average of 5.29 while naphthalene showed the lowest concentration at the average of 0.26. All the values were too low, at least to two orders of magnitude less than the permissible limit established by European Food Safety Authority, EFSA which is 1.0 µg/kg. These results are indicating wholesomeness of grain samples from PAHs contaminations.
Keywords : Polycyclic Aromatic Hydrocarbons, Determination, Grains, Staple Foods.