This pilot work will provide the experience and data to support subsequent funding applications powered to definitively establish the acute toxicities of e-cigarette vapor of various compositions (e.g., with and without nicotine, with and without flavoring) in persons with and without chronic lung diseases (e.g., asthma) on pulmonary ventilation and microvascular perfusion. Furthermore, confirmation of the hypotheses in this sample would provide important preliminary evidence of e-cigarette pulmonary toxicities to inform interim regulatory decisions, as well as potentially generating vivid images of e-cigarette harms that may be meaningful to the general public and therefore suitable for use in public education campaigns.