Evaluation of Human Exposure to Polycyclic Aromatic Hydrocarbons from Some Edible Oils and Shea Butter in Nigeria

The present study presents the results for the determination of the concentrations of the 16 USEPA polycyclic aromatic hydrocarbons (PAHs) in 30 samples of different types of vegetable oil (palm, groundnut, palm olein, soybean, cotton and castor seed oils) and shea butter in Nigeria. In addition, information is provided on the compositional patterns and sources of PAHs, as well as possible risks through consumption of contaminated products. Detection and quantification of the PAHs was carried out by means of gas chromatography-mass spectrometry (GC-MS). The PAH concentrations in the samples varied from 126 to 865 mu g kg(-1). The compositional patterns of the PAHs in the oil samples followed the order: 4R > 3R > 5R > 6R > 2R. The majority of the samples had individual PAH concentrations above the 2 mu g kg(-1) limit and all the samples surpassed the German Society for Fat Science limit of 25 mu g kg(-1) for the total PAHs. The estimated dietary intakes based on a 11.1 kg per capita consumption rate ranged from not detected to 133 ng BaP kg(-1) bw day(-1), 3.0 to 154 ng PAH2 kg(-1) bw day(-1), 11.7 to 178 ng PAH4 kg(-1) bw day(-1) and 13.2 to 234 ng PAH8 kg(-1) bw day(-1). The results indicate 5 to 669 chances in a million population of the risk of developing cancer. Source apportionment, as derived from PAH isomeric ratios, suggests that combustion processes, contamination by petroleum from transport trucks, as well as pyrolysis of fats, are the main sources of PAHs in these vegetable oils and shea butter.