Exposure to secondhand tobacco smoke (SHS) is associated with diverse health effects in
nonsmokers. Flight attendants (FA) who worked on commercial aircraft before the ban on
tobacco smoking (exposed FAs) had high, long-term levels of occupational exposure to SHS and
are a unique population for the study of long-term health effects of chronic exposure to SHS.
In previous studies, we have shown that many never-smoking SHS-exposed FAs to have
curvilinear flow-volume loops, decreased airflow at mid- and low-lung volumes, and static air
trapping (elevated residual volume to total lung capacity ratio [RV/TLC]), abnormalities that
are not diagnostic of overt Chronic Obstructive Pulmonary Disease (COPD), but do implicate
the presence of an obstructive ventilatory defect, and are consistent with what has been
recently described as preserved ratio impaired spirometry (PRISm).
The main objective of the study is to determine the effect of a bronchodilator to counter the
physiologic abnormalities that are observed in the population of never-smoking SHS-exposed
FAs as both proof of concept of the presence of an obstructive lung disease and as a possible
therapeutic option to counteract the adverse respiratory effects of chronic exposure to SHS.