Evaluation of potentially toxic element pollution in the benthic sediments of the water bodies of the city of Addis Ababa, Ethiopia

The concentrations of toxic and potentially toxic elements (As, V, Cr, Fe, Co, Ni, Cu, B, Ba, Sr, Zn, Mn, Pb and Cd) collected from benthic sediments in the water bodies of the city of Addis Ababa were investigated to evaluate their distribution and pollution levels. The average concentration of Cr, Mn, Pb, Ni, Fe, Cu, Zn and Cd exceeded the threshold effect level of the sediment quality guidelines. Many of the concentrations were higher than previously reported. The sediments were moderately to heavily polluted with Cr, non-polluted to severe with Cu, Zn and Pb elements, moderate to heavily polluted with Ni and non-polluted by As and Cd. The sediments were enriched with these elements in the increasing order As