Kishe, M. A.; Machiwa, John F.
Description:
Sediment samples were analyzed for Cd, Cr, Cu, Pb, Hg and Zn by AAS. The highest concentrations (ppm) for Cu (26.1F4.8), Hg
(0.2F0.05), Pb (30.7F5.6) and Zn (45.4F13.1) were found at approximately 25 m from the shoreline. Generally, heavy metals
concentration in the sediment decreased with increasing distance from the shoreline except for Cd and Cr whose highest concentrations were
found at approximately 2000 m from the shoreline.
The data also indicated that sediment samples which were collected at the shores within the urban area of Mwanza showed elevated levels
of Pb (54.6F11.1 ppm) and Zn (83.7F21.5 ppm). However, the highest concentrations of Cd (7.0F2.1 ppm), Cr (12. 9F1.0 ppm) and Hg
(2.8F0.8 ppm) were recorded at sampling stations which were adjacent to river mouths.