Résumé:
To limit the impacts of air pollution, it is important to estimate its deposition and effects 
on ecosystems and human health. We have chosen the lichen bioindication qualitative 
approach to evaluate the effects of the pollutants generated by gas stations on bioindicators. 
For this purpose, we conducted an inventory of epiphytic lichens in our study area and 
transplanted non-polluted samples to the same stations to assess the stress caused by this type 
of pollution. This inventory enabled us to identify species that are mainly toxi-tolerant. Then, 
in the laboratory, through histological sections and the determination of chlorophyll level 
carried out on the transplanted lichens, we noticed physiological and morphological 
disturbances due to stress gas station pollution