Metals pollution in freshly deposited sediments from river Mingoa, main tributary to the Municipal lake of Yaounde, Cameroon

Freshly deposited thirty six surface sediments from river Mingoa, main tributary to the Municipal lake of Yaounde in Cameroon, were sampled to determine the degree, sources and distribution of metals contamination. The concentrations of trace elements were measured by ICP-AES for the samples collected at different stations in January 2005. Generally, the concentration of metals (Ca, Mg, Na, K, Fe, Mn, Al, Cr, Co, Cu, Cd, Ni, Pb, Zn, Sr, Ba and Si) in the sediments reflected an anthropogenic inputs. The sediments were characterized by a high amount of organic matter (LOI) with a mean value of 12.44%. Enrichment Factors ( EF ) and Geoaccumulation Index ( I geo ) were calculated and the relative contamination levels were assessed at these sites. With the exception of Ni, the enrichment of toxic metals was high. Descriptive statistics and multivariate analysis (principal factor method) were used to assist the interpretation of elemental data. This allowed the determination of the correlations between the metals and LOI variability in the sediments, and the identification of four main factors loadings controlling by parent rocks, anthropogenic input, organic compounds and weathering of silicate minerals.