The Role of Macrophage Activation in Lung Injury Following Ozone Exposure

The purpose of the study is to better understand the mechanisms of lung injury from ozone exposure. Subjects will participate in two exposure sessions: filtered air and 0.2 ppm ozone. The exposure visits will be at least 2 weeks apart. Subjects will be asked to produce sputum through coughing after each exposure. The samples will be analyzed for macrophage activity.