Health risk linked to the contamination of quaternary groundwater by metallic trace elements in the West African coast: case of the west coast of Lomé, Togo

The problem of water contamination does not spare cities in Africa. The objective of this study was to assess the health risk linked to the consumption of water from wells in the Kodjoviakopé district (Lomé). The reason for this study was the desire to fill the information gap on the health quality of water used by the population of Kodjoviacope (West coast, commercial and Togo-Ghana border). To achieve this objective, the analysis of physicochemical parameters such as turbidity, pH and conductivity as well as certain metallic trace elements (cadmium, lead, iron, arsenic, and chromium) were analyzed in 24 water samples from the wells collected in March 2023. It appeared from the analysis of the results that the waters were highly mineralized, contaminated with cadmium, lead and arsenic; with strong contamination factors. In descending order of contamination factor, 220 times the WHO standard for arsenic; 33.92 times for lead and 1.76 times for cadmium were noted. The calculated risk quotient was greater than 1 for As, Cd and Pb in both adults and children as well as Cr in children. Overall, collected well water was contaminated. This therefore poses a public health problem. Raising public awareness of the effects of water contaminants and the policy of drinking water supply and sanitation in the area must be a priority for the country's authorities