 Sputum induction involves the inhalation of a mist of salt water to help produce a deep cough and a sputum sample from deep in your chest. This takes about 30 minutes. You will be given a pretreatment with a bronchodilator medication, and then inhale the mist for at least 1, and up to 3, 7 minute periods. Then you are asked to cough up some sputum from your chest, into a sample cup. Inhalation of the mist can cause coughing and sore throat but pretreatment with the bronchodilator should minimize these side effects. Spirometry is repeated after each inhalation of mist to detect any change in your airway size, or bronchoconstriction. If bronchoconstriction occurs, you will immediately be given a bronchodilator to reverse it. The sputum will be analyzed for markers of inflammation characteristic of your asthma. 