Assessment of Polycyclic Aromatic Hydrocarbons Contamination Level on Soil in Umuahia, Abia State, Nigeria

Abstract

Polycyclic Aromatic Hydrocarbons occurrence in the environment has been of great concern due to its toxicity to living organisms and the ecosystem. This present study assessed the contamination level of Polycyclic Aromatic Hydrocarbons in the soil around Umuahia municipality, Abia State. Soil samples were analyzed for the presence of the 16 US-EPA priority Polycyclic Aromatic Hydrocarbon (PAH) components, their concentrations. Soil samples were collected at five different locations at a depth of 0-30cm. The identification and quantification of the PAHs in the soil samples was carried out using the Aligent 7890B Gas Chromatography - Flame Ionization Detection (GC-FID). The physicochemical parameters of the soil samples were also analyzed using the American Standards of Testing and Materials (ASTM) standard methods. The results of the analysis revealed that amongst the 16 US-EPA priority PAHs, eight (8) were detected in the soil samples. The total concentration of the PAHs detected in the study area were in this order: the order of fluorene> benzo(a)anthracene> pyrene>dibenzo(a,h)anthracene> anthracene> benzo{ghi}perylene> indeno{1,2,3-cd}pyrene> acenaphthene with total concentrations of 10.64mg/kg, 10.16mg/kg, 2.784mg/kg, 9.37mg/kg, 9.01mg/kg, 7.51mg/kg, 5.32mg/kg and 0.443mg/kg > 0.21mg/kg respectively. The study area was found to be contaminated with PAHs with more HMW PAHs (4-ringed) than LMW PAHs (3-ringed PAHs). PAH diagnostic ratio showed possible sources of PAHs to be pyrogenic, petrogenic and petroleum combustion.