This study aims to ascertain whether standard exercise stress testing can detect subclinical cardiopulmonary disability in subjects with significant exposure to second hand tobacco smoke (SHS). The ultimate goal of this study is to contribute to the understanding of SHS-related illnesses, and to the care of future patients with SHS exposure.
The main hypothesis of this study is that exposure to the secondhand tobacco smoke (SHS) in the confined workspace of commercial aircraft prior to the ban against cigarette smoking is responsible for long-term damage to the lungs of nonsmoking flight attendants. Although only some flight attendants show evidence of this damage on their lung function at rest, the majority of the flight attendants will have abnormal diffusing capacity during exercise as the damage may be too subtle to be detected with lung function measurements at rest. To test these hypotheses, we will compare pre- and post-ban flight attendants to each other and to two groups of age-matched, nonsmoking controls living at sea level stratified on the basis of SHS exposure. The results of our study should permit us to determine whether SHS alone could account for the lung damage in flight attendants, or whether some more complex interaction (involving cabin factors such as ozone, altitude, radiation and SHS) may be involve.