Evaluation of Total Hydrocarbon (THC) levels in oil polluted coastal areas of South Eastern Nigeria

Abstract

Analysis of water, sediment and biota for total hydrocarbon (THC) levels five months after the Mobil oil spillage in the coastal areas of Cross River State, South Eastern Nigeria, was carried out. THC levels in water, sediment and biota samples were determined by colorimetric method after extraction with distilled n-hexane. Result showed elevated THC mean levels in water (149+81.11 mg/l), sediment (339.2 + 245.7 mg/kg) and biota (198.9 + 50.08 mg/kg), indicating a polluted environment. THC levels in water at all sampling locations were above 10mg/l being the maximum recommended limit of FEPA. In sediment and biota, THC values exceeding 100mg/kg and 25mg/kg, respectively, were observed, indicating that sediment and biota were highly impacted. THC levels in water correlated significantly (r = 0.632) with THC levels in the sediment (P = 0.05). Bioconcentration factors (BCFs) in 70% of the water samples were higher than unity. Although there was low BCF in about 70% of sediment samples, BCF in water significantly correlated (r = 0.689) with BCF in sediment (P = 0.05), indicating that the more the THC levels in the water column in relation to sediment, the more the biota were impacted.



Key Words: Oil spillage, Total hydrocarbon, Bioconcentration factor, Polluted environment, Coastal Areas.

[Global Jnl Environ Sci Vol.2(1) 2003: 1-9]