There are 2 parts to this study. In Part A, two EBC samples will be collected from each participant. Some participants will be have one EBC sample taken by the EcoScreen and the other taken by the R-Tube; other participants will have both samples taken by the R-Tube. In Part B, asthmatics taking ICS, asthmatics not taking ICS, and nonasthmatics will give 2 EBC samples each via the R-Tube.