Ecological and Health Assessment of Heavy Metals Present in the Soil of E-Waste Collection, Recycling and Dismantling Sites in the Region of DAKAR, Senegal

Soil pollution from waste electrical and electronic equipment is a growing concern in Africa. The heavy metals contained in this waste are now one of the main sources of pollution and the handling of waste electrical and electronic equipment (WEEE) is increasingly a health and environmental concern. In Dakar, several handling points of this equipment were identified and our study investigated the presence of trace metals in the soil of e-waste handling sites in the Dakar region and about the spatial distribution of Pb, Cd, Cu, Cr, Fe, As, Hg and Mn according to the activity carried out on these sites. Three categories of activity were identified, namely collection, dismantling and recycling and a control site. The results show an abundance of metals for the collection and recycling sites which were such as Fe> Mn> Pb> Cu> Cr> Cd> As> Hg. In contrast, at the dismantling sites, the average total concentration of these elements was classified as Fe> Pb> Mn> Cu> Cr> As> Cd> Hg and that of the control site was Fe> Mn> Cu> Pb> Cr> Cd> As> Hg. The estimation of the potential ecological risk (Er) in relation to the control site shows an average risk coefficient for Fe, Mn and Cr below 40 for all sites, as well as for As in the collection and recycling sites and for Cu in the collection sites. Pb, Cd and Hg showed an average level of ecological “very high risk” for all sites and As also showed a “very high risk” for the dismantling sites for an ecological risk index of “Very high ecological risk” (RI> 600) for all sites associated with a non-carcinogenic risk greater than 1 for all site categories.