Concentrations, health risks and sources of polycyclic aromatic hydrocarbons in Nigerian honey

The concentrations of the US EPA 16 priority polycyclic aromatic hydrocarbons (PAHs) were measured in honey samples collected from different regions of Nigeria with a view to providing information on the extent of contamination, regional profiles, sources and risks of PAHs in this food type. The concentrations of the PAHs were determined by using gas chromatography-mass spectrometry after extraction by ultra-sonication with n-hexane and dichloromethane. The concentrations of ∑16 PAHs in the honey samples ranged from 169-522 μg kg-1, 97.2-1980 μg kg-1, 180-641 μg kg-1 and 122-357 μg kg-1 for South- East, South-West, Niger Delta, and North Central regions respectively. The compositional patterns of PAHs in the analyzed honey samples followed the order: 5-rings>4-rings>3-rings>6-rings>2-rings. The estimated daily intake values from consumption of these honey samples ranged from not detected (nd) to 1.9 ng kg-1 bw day-1, nd to 5.9 ng kg-1 bw day-1, nd to 18 ng kg-1 bw day-1 and 0.6 to 33 ng kg-1 bw day-1 for BaP, PAH2, PAH4 and PAH8 respectively. The incremental life cancer risk and margin of exposure values for the majority of the samples indicate that there is no risk associated with the consumption of these honey samples. The PAH isomeric ratios and principal component analysis indicated that combustion of fossil fuels, natural gas and biomass, and automobile emissions were the main sources of PAHs in these samples from the different regions of Nigeria.