Health Risk Assessment of PAHs from Wheat (Tritcum specie) Bambara Nut (Vigna subterranea) and Pigeon Peas (Cajanus cajanifolia) Consumed in Nigeria

Abstract

Polycyclic aromatic hydrocarbons, PAHs are carcinogenic and genotoxic in nature and have been of worldwide concern. This study aimed at determining the PAH contamination levels in types of  wheat  (Tritcum specie), bambara groundnut (Vigna subterranea) and pigeon peas (Cajanus cajanifolia) commonly consumed in the eastern part of Nigeria and assess the health risk associated with their consumption. The grain samples were analyzed of sixteen priority PAHs using gas chromatography coupled with flame ionization detector, GC-FID after extraction by sonication. Estimation of daily intakes were carried out using adult male and female consumers while margin of exposure was used to assess the health risk applying bench mark dose levels for the indicators-BaP, PAH2, PAH4 and PAH8. The sixteen PAHs were detected in all the analyzed grains. The ∑16 PAHs concentrations (× 10¯²µg/kg) detected ranged from 25.004±20.553 in white pigeon peas to 36.493±20.305 in red pigeon peas. The eight probable carcinogenic PAHs (∑PAH8) detected ranged from 10.913±4.295 to 17.444±7.023 also in white and red pigeon peas respectively. From the estimation of daily intake calculated, the total dietary exposure of male (41.42 µg/kg bw/day) was less than that of female (48.24 µg/kg bw/day) implying that adult female are more exposed. The MOE for adult male individual ranged from 49,893 in pure white bambara groundnut to 392,943 in pigeon peas. While for adult female individual, the values of MOE ranged from 48,110 in bambara groundnut to 336,770 in pigeon peas. The values of margin of MOE obtained for all the indicators were much higher than 10000 which according to EFSA indicate low concern for human health and considered low priority for risk management actions. The PAHs values detected were all below 1.0 µg/kg which is the permissible limit established by EFSA. Based on these facts, these grains are safe for consumption.