Levels of Hg and Cd in selected biological species from the river Pra- a study of pollution of the river Pra estuary

Abstract

This thesis determined the level of mercury and cadmium in selected biological species namely tilapia (Tilapia zillit), mudfish (Clarias slIbmargillatlls), prawns (Pellaeus //Iolladall) , crabs (Carcilllls 11laellas) and Molluscs Periwinkle (Gastropod) from the River Pra Estuary using. The samples were taken every fortnight from four sampling sites from Beposo to Shama Beach in the Western Region of Ghana for two months. That is form 10105/06 to 29106/06. During the period a total of eighty (80) samples were collected and analyzed and the levels of mercury determined in the muscles of the various biological species were between 0 and 0.00808 ± 0.0009hlg/g while the levels of cadmium were between 0.0010 I ± 0.00013 flg/g and 0.02024 ± 0.00263 flglg. But all the values are well below European Union acceptable limits of 0.05flg/g.