The research plan proposes translational studies in relevant animal models and human subjects in order to identify host (genetic) susceptibility factors that confer vulnerability to the prototypal air pollutant, ozone. The results will have significant impact upon, and aid in, understanding mechanisms regulating pro-oxidant lung injury, production and secretion of airway mucins, and clearance of respiratory mucus, and adverse health effects, that occur during and following exposure to airborne respiratory irritants.