Heavy Metals Accumulation in Sediment Cores of the Municipal Lake of Yaounde, Cameroon

Heavy metal (Pb, Zn, Cu, Cr, Ni, Mn and Cd) concentrations were investigated for the first time in core sediments of the Municipal Lake of Yaounde, Cameroon. The area under study receives domestic raw sewage from surrounding populated neighborhoods through River Mingoa, main tributary of the lake. Other activities like automobile service stations, garages, non operational effluent treatment station, anarchistic disposal of domestic waste and the use of chemicals in the marshy zone for agriculture and mosquitoes control are carried out in the sloping side of River Mingoa and the lake. Levels of Pb, Zn, Cu, Cr and Cd in sediment cores were above average shale values. Except for Ni, the contamination factor (C ) of other metals was greater than 1. f The geoaccumulation indices (Igeo) indicate that the lake sediment cores are moderately to very strongly polluted with Pb, Zn, Cu, Cr and Cd. This accumulation is strongly related to the cited activities. They were very high positive correlations among the metals and principal component analysis (PCA) reveals three components in the upper layer (79.863%), two components in the middle (75.203%) and lower (73.181%) layers, respectively.