ABSTRACT

This study investigated the presence of 16 Polycyclic Aromatic Hydrocarbons in selected commonly consumed crops in industrialized area of Enugu state Nigeria.( Man ihotesculenta) (Cassava), Dioscorea rotundata. (Yam), Colocacia antiquorm(Cocoyam), Telferia occidentalis(Pumpkin), Vernonia amygdalina (Bitter leaf), Tali numtriangulare (Water leaf), Citrus sinensis (Orange), Chrysophyllum albidun (Star Apple), Carica papaya (Pawpaw), Cocos nucfera (Coconut), Cola acuminata (Kolanut), Elaies guineensis (Palm nut). PAHs are group of organic compounds very stable composed by two fused aromatic rings of carbon and hydrogen atom that have heating systems. Total concentration of PAH QPAH) in all analyzed sample was found to be 60.25mg/kg dry weight. PAH values for the individual samples followed the trend palmnut>purnkin> bitter leaf> Cocoyam> water leaf >Cassava>pawpaw> yam and was within the range of 0.87 (for yam) to 21.79 mg/kg dry weight (for palm nut). These values exceed the regulatory limit of 0.2mg/kg dry weight set by the European Union. palmnut and pumkin had elevated levels of PAH. This could reflect the biological properties of these plants to bio- accumulate large amounts of recalcitrant pollutants (PAH).Combined concentration of individual PAH in all samples was in the decreasing order B(a)F> FLA>B(a)A>CHR>B(a)P>PYR>D(a,h)A>B(k)F>ACY>ANT>PHE>FLO>ACE> NAP>tmNAP>I(c,d)P. The first eight PAR (in terms of abundance) are high molecular weight PAR associated with prolonged effects due to less susceptibility to microbial degradation. Five (5) out of these eight PARs namely benzo[b] fluoranthene, benzo [a] anthracene, chrysene, Benzo(a)pyrene and benzo[k]fluoranthene are implicated in carcinogenesis according to the California Environmental Protection Agency. Consequently, the population of people living in and around the study sites may be predisposed to high risk of cancer due tolong exposure to PAH compound through contaminated soil and food crops. Benzo(a)pyrene (BaP) in analyzed samples was; 2.41 mg/kg dw,1.84 mg/kg dw,0.0) mg/kg dw,0.08 mg/kg dw,0.03 mg/kg dw,0.02 mg/kg dw and 0.01 mg/kg dw for pumpkin, palm nut, cocoyam, pawpaw, water leaf, cassava and yam respectively. Thus making pumpkin and palm nut have high concentration of PAHs and suggesting their use as bio-monitoring plants. These values are above the DPR intervention limit of 0.01 mgkg-1 dw for food. Key Words: Polycyclic Aromatic Hydrocarbons, Daily Intake, Life Time Cancer Risk, Health Risk Assessment