The use of super carburant involves a lot of lead particles by the vehicles. This type of pollution specially affects the urban populations and the environment. This phenomenon is emphasized in the big cities like Dakar where more than 60% of the national car park move. This study shows that the trees can be used as indicator of lead pollution level. Unfortunately, the estimation of the pollution level isn't always easy whereas numerous factors can play a role in the mechanism. In this study, we have shown that the atmospheric pollution of Dakar by the muffler gases is a real fact.