This study assesses the levels of petroleum pollution and its impact on the aquatic ecosystem around Effurun roundabout in Delta State, Nigeria. The distribution of n-alkanes and polyaromatic hydrocarbon (PAH) in surface water contaminated with crude oil and their implications for environmental and human health were analyzed. Total Petroleum Hydrocarbon (TPH) was determined using Gas Chromatography/Flame Ionization Detector (GC/FID). Four surface water samples were collected from the study area and one from the control site six months after an extensive oil spillage and petroleum-induced fire incidence in June 2016. The mean value of TPH obtained in surface water was 25.885±5.105mg/L. The study area had a significantly higher concentration of TPH than the control site. The concentrations of AHC, PAH, and PHC for the study area were recorded as 16.910±3.018, 8.944±2.122, and 25.885±5.105, respectively, while the concentrations of AHC, PAH, and PHC for the control samples analyzed were 1.716, 0.349, and 2.065, respectively. The study found positive correlations between aliphatic hydrocarbon and petroleum hydrocarbon concentrations, as well as between polyaromatic hydrocarbon and petroleum hydrocarbon concentrations, indicating similar sources and transport mechanisms for the pollutants. However, a weak positive correlation was found between aliphatic hydrocarbon and polyaromatic hydrocarbon concentrations, suggesting potential differences in sources and transport mechanisms. The study area is under pollution threat, and the clean-up done previously after the spill was insufficient to restore the integrity of the environment. The findings highlight the need for urgent remediation measures to prevent further damage to the ecosystem and to safeguard human health.
Key Words: Crude oil pollution, water quality, n-alkanes, polyaromatic hydrocarbon, Effurun, Delta State