28 Toxicol. Environ. Health. Sci. Vol. 8(1), 28-42, 2016 The concentrations of the US EPA 16 priority polycy- clic 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 concentra- tions of the PAHs were determined by using gas chromatography-mass spectrometry after extraction by ultra-sonication with n-hexane and dichlorometh- ane. 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 expo- sure values for the majority of the samples indicate that there is no risk associated with the consump- tion of these honey samples. The PAH isomeric ratios and principal component analysis indicated that combustion of fossil fuels, natural gas and bio- mass, and automobile emissions were the main sources of PAHs in these samples from the different regions of Nigeria. Keywords: Honey, Polycyclic aromatic hydrocarbons, Risk assessment, Nigeria Introduction Honey is a natural product produced by Apis mellifera bees from the nectar or secretions of plants, and does not usually contain any additives or preservatives 1 . It contains a number of nutritionally valuable compounds and has healing, prophylactic, anti-oxidative, anti-bac- terial and immune-enhancing properties 2,3 . Honey is made up of a mixture of carbohydrates, such as fruc- tose (25-45% m/m), glucose (25-37% m/m), maltose (2-12% m/m) and sucrose (0.5-3% m/m) with traces of other sugars, and water (14-18% m/m) 4 as well as small amounts of a wide array of vitamins, mineral substances (0.1 to 1.0% m/m) 5 , amino acids and antioxidants 1 . The colour, flavour, carbohydrate composition and mineral, amino acid and antioxidant content of honey often var- ies with floral types 1 . The concentrations of contami- nants in honey reflect the conditions of the environ- ment and bee-keeping practices. Since the forage area of the bee hive is very large (more than 7 km 2 ) and the bees come in contact with the basic components of the environment (air, soil and water), the concentrations of contaminants in honey reflect their amounts in the whole region 4 . Thus, honey can serve as a useful envi- ronmental marker and bioindicator for monitoring en- vironmental contaminants 6-9 . Despite the known nutri- tional and therapeutic properties of honey, the occur- rence of xenobiotics, such as metals, pesticides and polycyclic aromatic hydrocarbons, in honey may con- stitute a serious threat to consumers. Polycyclic aromatic hydrocarbons (PAHs) are a di- verse group of over one hundred (100) organic com- pounds consisting of two or more fused aromatic rings 10 and/or pentacyclic rings in linear, angular or cluster formations 11-13 . PAHs are primarily produced by the Chukwujindu M. A. Iwegbue 1 , Godswill O. Tesi 1 , Grace Obi 2 , Grace E. Obi-Iyeke 3 , Ufuoma A. Igbuku 1 & Bice S. Martincigh 4 1 Department of Chemistry, Delta State University P.M.B. 1, Abraka, Nigeria 2 Department of Chemistry, Federal University of Petroleum Resources, Effurun, Delta State, Nigeria 3 Department of Botany, Delta State University P.M.B. 1, Abraka, Nigeria 4 School of Chemistry and Physics, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban, 4000, South Africa Correspondence and requests for materials should be addressed to C. M. A. Iwegbue (maxipriestley@yahoo.com) Received 9 July 2015 / Received in revised form 27 December 2015 Accepted 8 January 2016 DOI 10.1007/s13530-016-0259-z ©The Korean Society of Environmental Risk Assessment and Health Science and Springer 2016 pISSN : 2005-9752 / eISSN : 2233-7784 Abstract Concentrations, Health Risks and Sources of Polycyclic Aromatic Hydrocarbons in Nigerian Honey