POLYCYCLIC AROMATIC HYDROCARBON IN SEDIMENT, GROUND AND SURFACE WATER RESOURCES IN COASTAL AREAS OF ONDO STATE, NIGERIA

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are of global concern due to their harmful effect on the health of human and the environment. They are known as persistent organic pollutants and linked to severe health effects in humans and ecosystem. This study aimed to investigate the presence and types of these hydrocarbons including assessing their distributions in groundwater water, surface water and sediment in Igbokoda, Irele and Okitipupa coastal areas of Ondo State, Nigeria. The watersamples were extracted with liquid-liquid extraction while the sediment samples were extracted with an ultrasonic bath extractor. The extracts were cleaned with alumina as adsorbent and analyzed using a gas chromatograph coupled to a mass spectrometer. The results showed wide variations in the concentrations of the analytes of interest in the different matrices studied. The total mean concentration range of these pollutants in the samples from the well, borehole, surface water, and the sediment were: 0.15 ± 0.31, 0.11±0.52 to 0.90± 0.28, 0.05±0.02 to0.11±0.52 and 0.16±0.14 to0.21±0.17, respectively. The result revealed that the concentrations of most of these contaminants were higher than the maximum permissible limit of PAH in drinking water and sediment. The contamination level was higher in the borehole water source than the others. The study concluded that all the investigated matrices were contaminated with these pollutants. The study recommended the enactment of new laws of regulating activities leading to the emissions of these pollutants by the Nigerian government inorder to safeguard the environment and human health.