Exercise in Air Pollution and Lung Health in Asthmatics

Inclusion Criteria: * mild-moderate asthmatics with controlled treatment (definition of "mild": percent fall index at eucapnic voluntary hyperpnea (EVH) test on screening day between 10-15%; "moderate": percent fall index at EVH test on screening day between 15 - 20%). * men and non-pregnant women Exclusion Criteria: * any history of uncontrolled respiratory or cardiac disease * pregnancy * allergic reactions to lidocaine and salbutamol * any recent infections or orthopaedic nasal issues/injuries that may interfere with the insertion of the catheter needed to assess expiratory flow limitation or work of breathing * claustrophobia in small rooms, comparable to the air pollution chamber used for this study. * English as a second language (ESL) - participants who are not able to understand the risk that may be associated with the participation in this study due to language difficulties after following the University of British Clinical Research Ethics Board Guidance Notes 13.2.1. (ESL participants will be given a consent form in the most appropriate language or an appropriate translator will be present during the initial consent process).