Environmental contamination by Polycyclic Aromatic Hydrocarbons (PAHs) has been of great concern due to risk to human health and the ecosystem. This study was carried out to identify the sources and fate of PAH contamination in agricultural soils of Imo River Watershed, Imo State, Nigeria. A total of 8 soil samples (0- 30cm) were randomly collected from different activity areas on the watershed and analyzed for the presence of the 16 US-EPA priority PAHs. The identification and quantification of the PAHs in the soil samples were carried out in accordance with EPA 8270: (GC-MSD). The results of the analysis revealed that amongst the 16 USEPA priority PAHs, eight of them were detected in the soil samples. The total concentration of PAHs detected in the study area were Naphthalene (0.146mg/kg), Acenaphthylene (0.010mg/kg), Acenaphthene (0.210mg/kg), Phenanthrene (0.021mg/kg), Anthracene (0.041mg/kg), Flouranthene (0.130mg/kg), Pyrene (0.020mg/kg) and Benzo(b)fluoranthene (8.641mg/kg). The decreasing order for individual PAHs concentration in the soil samples within the study area were Benzo(b)Flouranthene>Acenaphthene>Naphthalene>Fluoranthene>Anthracene>Ph enanthrene Pyrene > Acenaphthelyn. The total PAHs concentrations recorded in the soil of Obowob zone were generally observed to be higher than Okigwe zone. This study revealed that Imo River watershed of Imo State is gradually being contaminated with PAHs from abattoirs and auto-mobile repair activities, as the results showed that the concentrations of some PAHs in the study area were beyond maximum permissible limits of 0.5mg/kg for individual PAHs and 10mg/kg for total PAHs stipulated by National Environmental Standards and Regulations Enforcement Agency (NESREA), which is an indication of anthropogenic contribution. There is need for public education on the consumption of vegetables grown in and around abattoirs and areas dominated by automobile repair activities.
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