Polycyclic aromatic hydrocarbons (PAHs) pollution in marine waters and sediments at the Tema Harbour, Ghana

Abstract

Polycyclic aromatic hydrocarbons as a major pollutant from automobile exhaust, combustion of all forms of fuels and other industrial activities, find their way into water bodies which may have adverse effect on aquatic life. Tema, being an industrial city, has no records of PAHs pollutants hence this study at the Tema Harbour seeks to measure their concentrations which may affect water and sediment quality. This will give baseline guidance to the authorities in the control of pollutants. Samples of surface sediments and water were collected from 10 sites at the Tema Harbour complex in Tema, Ghana, comprising of the canoe landing site, the inner fishing harbour, the outer fishing harbour and the main harbour. The concentrations of the polycyclic aromatic hydrocarbons (PAHs) were analysed by GC with FID detection after Soxhlet and Liquid-liquid extractions were performed on the sediments and water, respectively, using dichloromethane. A broad distribution of the PAHs were identified with the total mean concentration of ∑20 PAHs ranging from 28.6 to 190.3 µg/g w.wt in sediments and from 33.2 – 84.5 µg/L in water. The levels of PAHs in the sediments and water at the canoe landing site were higher than those at the other basins of the harbour complex. Concentrations are however, equally distributed in the inner and outer fishing basins while variations were observed at the different sampling sites within the main harbour. The result from this study provides a valuable range of PAHs concentration that can help in the control of pollutants and in future assessment of water and sediment quality.