Seasonal Trend of Polyaromatic Hydrocarbons (PAHs) in Sediments from River Ethiope in the Niger Delta Region of Southern Nigeria

Seasonal trends of polycyclic aromatic hydrocarbon in the sediment of River Ethiope in Delta State, Southern Nigeria were assessed in this study. Samples were taken from six different points at Ethiope River along its banks during the dry and rainy seasons. Samples were extracted using soxhlet apparatus and analysed with gas chromatography-flame ionization detector (GC/FID). The results obtained for the PAHs concentration ranges from 184.73 µg/kg – 3679.13 µg/kg for dry season and for rainy season, some stations were below detection limit (BDL) to a maximum value of 693.43 µg/kg. The result clearly shows that the total concentration of polycyclic aromatic hydrocarbon detected in the dry season was higher than those of the rainy season. Similarly, more PAHs compound of higher and lower rings were found in the dry season than in the rainy season in sediment samples. Although, the PAHs concentrations were quite low which indicated no danger status from the consumption or dermal contact for humans’ point of view, however, the levels can cause adverse effects for lower aquatic organisms which are exposed to the sediments on a daily basis. Therefore, persistent monitoring and strict adherence to responsible waste discharge should be upheld by all manufacturing and agro industries located in the study area in order to avoid deleterious effects of the biodiversity in the water bodies as well as ensuring safety of the consumers.