Total Petroleum Hydrocarbon Concentration in Surface Water of Cross River Estuary, Niger Delta, Nigeria

An increase of petroleum hydrocarbons levels in the aquatic environments has become worrisome because of their deleterious impact not only on marine organisms but also its effect on human health. In view of the devastating effect of total petroleum hydrocarbons, this study was carried out in order to ascertain the level of contamination of Cross River estuary. Total petroleum hydrocarbon levels were determined in surface water samples collected from various sampling points along Cross River estuary using Gas Chromatography – Flame Ionization Detector (GC-FID) instrument. Results obtained indicated that the surface water was contaminated with total petroleum hydrocarbon with mean concentration ranging from 13.16181±1.485 to 24.85462±8.058 mg/l compared to the control sample with concentration of 9.68200±0.233 mg/l. Moderately high molecular weight hydrocarbons were dominant in all the sampling stations except in station 3. It was further observed that the level of total petroleum hydrocarbon in this study was high relative to Nigerian permissible limit of 10 mg/l in water. This poses a serious risk to the survival of aquatic organisms and also affects the quality of water used for various purposes.