ABSTRACT

Polycyclic Aromatic Hydrocarbons (PAHs) are a group of environmental contaminants (pollutants) that emanate from incomplete combustion of fuel or high temperature pyrolysis of fats and oil. Using Gas chromatographic-mass spectrometry, an Incremental Lifetime Cancer Risk (ILCR) assessment model and Dietary daily Intake (DDI), the bioaccumulation and cancer risk of 16 USEPA priority of Polycyclic Aromatic Hydrocarbons was investigated in 12 commonly consumed food crops at Ishiagu, Ebonyi state Nigeria. The total PAHs in food samples grouped into tubers, fruits, nuts and vegetables ranges from: 0.90 ± 0.10mg/kg to 5.26 + 0.04mg/kg Telfairia occidentalis, 0.70 ± 0.01mg/kg to 2.59 + 0.01mg/kg Talinurn iriangulare and 0.03 ± 0.01mg/kg to 1.88 ± 0.01mg/kg Vernonia amygdalina, while the high molecular and carcinogenic PAHs are represented thus: 0.03 ± 0.01mg/kg to 1.78 ± 0.03mg/kg Telfairia accidentalis, 0.39 ± 0.02mg/kg to 3.68 ± 0.02mg/kg Talinuni triangulare and 0.06 ± 0.01mg/kg to 1.70 + 0.01mg/kg Vernonia amygdalina. In tubers, these PAHs (LMW) are below detection level(BDL) in yam and cassava, while they range from 0.01 ± 0.00mg/kg to 0.08 ± 0.01mg/kg in cocoyam. The HTvIW are also below detection level in yam and cassava while they have values ranging from 0.00 ± 0.00mg/kg to 1.41 ± 0.09mg/kg in cocoyam. In the selected nuts, LMW and non-carcinogenic have ranges of 0.01 ± 0.00mg/kg to 0.15 ± 0.01mg/kg Cocos nucifera, 0.00 + 0.00 to 0.12 ± 0.00mg/kg Cola acurninata and 0.01 ± 0.00mg/kg to 4.95 ± 0.05mg/kg Eiaeis guineensis. Their respective value range of 1-IlVIW and carcinogenic are 0.00 ± 0.00 to 0.51 ± 0.01 Cocos nuc4fera, 0.00 ± 0.00 to 0.68 ± 0.01mg/kg Cola acurninata and 0.00 ± 0.00 to 0.90 ± 0.01mg/kg, in palm kernel. The selected fruits show that the LMW and non-carcinogenic PAHs are as follows: 0.00 ± 0.00 to 0.16 + 0.01mg/kg Carica papaya and 0.02 ± 0.01mg/kg to 0.17 ± 0.01mg/kg Chrysophyllurn albidurn while the HMW and non-carcinogenic are of same value range for both pawpaw and star apple (0.00 ± 0.00 to 0.09 ± 0.01mg/kg). The concentrations of PAHs in the vegetable samples are more than the other samples (tubers, nuts and fruits). Also, the accumulation of lower molecular weight compounds of PAHs is more than higher molecular weight PAHs, while yam, cassava and orange PAHs were found to be below detection limit. With the values obtained from DI and LCR of different groups of individual, male and female adult and male and female children, a lower rate of DI was found in children whereas LCR and DI were predominant in adults.