Authors : A. Sam, D.K. Dodoo, D.K. Essumang, C.K. Adokoh, G. Doe Nutifafa and Y. Ameyaw
Abstract: Instrumental Neutron Analysis by Americium-Beryllium radioisotope neutron source was employed for the determination of mercury and cadmium from eight different sites of the Pra and Ayensu estuaries in Ghana. Mercury and cadmium were identified in μg g-1 levels and values correlated with the pH values of water column and soil samples. Substrates like the Blue Tilapia and the European Green Crab were used as bioaccumulation indicators for the mercury levels in the various samples. A summary of the mean, minimum and maximum soil/water mercury and cadmium concentrations detected for the 8 sites with the widest geographical distribution; river bank at Beposo showed a maximum of 3.95x10–3 μg g-1 of mercury which is far below the Environmental Protection Agency’s permissible limit of 0.134 μg g-1. Insignificantly low levels of mercury concentrations were analyzed in shoulder soils and water samples over the period of the study. A significantly high levels of concentrations of mercury existed in the riverbed sediments as compared to that for the riverbank sediments, water and the shoulder soils. The degree of concentrations of mercury showed that mercury and cadmium concentrations decreased significantly and gradually as one moved from Beposo to the Shama beach through Bosomdo and Krobo. Mercury and Cadmium residues were also recorded in both European green Crab and blue tilapia. The levels of the two elements were slightly high in the Crab as compared to the Blue Tilapia. The differences could be attributed to the fact that the Crab is a bottom-dweller and predator. The concentrations of the two elements were far below the world permissible levels.
A. Sam, D.K. Dodoo, D.K. Essumang, C.K. Adokoh, G. Doe Nutifafa and Y. Ameyaw, 2010. Assessment of Levels of Cadmium and Mercury of Two Estuaries in Two Regions of Ghana. Research Journal of Applied Sciences, 5: 40-46.