POLLUTION AND HEALTH RISKS RELATED TO HEAVY METAL CONTAMINATION OF WATER RESOURCES IN THE KOKO RIVER WATERSHED IN THE CITY OF KORHOGO (NORTH OF COTE DIVOIRE)

The present study aimed to evaluate the distribution of Hg, As, Cd, Cr, Cu, Ni, Pb and Zn as well as the health risks in surface water in northern Cote dIvoire.The pollution of the waters was determined by pollution indices. The human health risks were assessed using non carci nogenic and carcinogenic risks indices.In surface waters, concentration s of trace metals (Hg, As, Cd, Cr, Cu, Ni, and Zn) in groundwater respected the guideline values. However, the total concentrations of Pb in surface waters exceeded the guideline values. The pollution indices HPI, HEI, and WQI revealed very low pollution in the surface waters. The total non-carcinogenic risk values for Hg, As, Cd, Cr, Cu, and Ni in surface waters varied from 1.02,10, 3 to 8.22,10,1 , indicating low adverse on human health effects.In contrast, the total non-carcinogenic risk values for Pb and Zn suggest adverse on human health effects.