Clinical measurements

All measurements were taken at the time of enrollment from 2015 to 2020, which was ≥ 15 years after their last possible exposure to airline SHS (Fig 1A).²⁴ Information about demographics, comorbidities, and current medications was collected from all subjects at enrollment. Participants answered the tobacco smoke exposure questionnaire modeled after Eisner et al²⁷ and adapted from Arjomandi et al,²⁵ which collected detailed smoking and SHS exposure history, including prenatal, home, adult nonairline work, and adult airline work exposure. The questionnaire also collected information about exposures to vapors, gas, dusts, and fumes (VGDF).