Résumé : On the bronchi walls, the bronchial mucus forms a thin layer that protects the lung by capturing inhaled pollutants. Due to the curvature of its interface with air, the layer is submitted to curvature effects that interact with its rheology. Based on lubrication theory and 3D simulations, we show that these effects might move overthick mucus layers in the airway bifurcations. This movement could disrupt the mucociliary clearance and break the layer thickness homogeneity.