This thesis was a contribution to the CORUS-POLCA (French acronym for " POLlution des Capitales Africaines ") program with the aim to characterize particulate pollution on traffic sites of two West-African capitals (Bamako, Mali and Dakar, Senegal) and to study aerosol biological impacts on lung inflammation. Urban particulate pollution with levels much higher than WHO norms, are in the focus due to intense African traffic sources and domestic fires. In this context, fundamental research of this thesis is centred on the following key scientific questions: - What is the chemical speciation of aerosols by size classes for black carbon, organic carbon, inorganic species, and trace elements for the two sites of POLCA program ? - What is the toxicity of these combustion aerosols and the oxidative stress levels ? - What is the link between aerosol size differentiated composition and inflammation markers for each source ? - What is the link between aerosol exposure and aerosol dose within the respiratory tract ? To tackle these questions, samples obtained during the intensive campaigns in Bamako (January 2009) and Dakar (December 2009) have been chemically analyzed to obtain differentiated aerosol chemical composition within size classes. All these measurements are conducted to a well physico-chemical characterization of particles in addition to source contributing determination using multivariate models (PCA, PMF). This study has been coupled to in vitro biological studies on sampled aerosols on the two sites. Such coupled studies allow to further understand the complex relationship between emissions source/aerosols chemistry/size distributions and biological health impacts. Finally, in this study, the DEPCLUNG (DEPosition, Clearance, LUNG) model was developed to evaluate chemically/size exposures to aerosol particle size distributions and calculate their respective concentrations/doses in the different compartments (trachea, bronchial, bronchiolar, alveolar) of the human respiratory tract. The conjunction of three themes, namely characterization of the urban particulate pollution in West Africa and its sources, its toxicological impact and dose modeling in the respiratory tract results in the multidisciplinary innovative character of the thesis.
