Deployment-related respiratory health: bridging the gap between clinical and epidemiological associations and disease mechanisms: an official American Thoracic Society Workshop Report.

Land-based military deployers to Afghanistan and/or Southwest Asia (SWA) encountered exposure to high concentrations of respirable particulate matter (PM) from multiple sources, including desert dust, burn pit smoke, and military occupations. Adverse lung health effects following deployment have been noted, including upper and lower respiratory tract symptoms, asthma, and small airway and other abnormalities on lung biopsy. The American Thoracic Society (ATS) convened a workshop in 2018 to review studies assessing postdeployment respiratory health, describe emerging research, and highlight knowledge gaps. Progress on understanding postdeployment health prompted a second ATS workshop to update current knowledge by (1) reviewing new studies linking exposure assessments to symptoms and/or clinical disease; (2) describing the spectrum of lung pathology reported in previously deployed personnel; (3) evaluating current knowledge of long-term health outcomes after deployment; (4) reviewing data from recent experimental models of deployment-related respiratory diseases (DRRDs); and (5) providing recommendations for future research priorities. Workshop participants agreed that there is substantial evidence linking deployment-related exposures to respiratory symptoms, pulmonary diagnoses, and lung pathology. Knowledge gaps include understanding: (1) the extent and mechanisms through which specific exposures result in impaired pulmonary function, small airways disease, and potentially future chronic pulmonary diseases; (2) the contribution of exposure-related foreign material in the lung to clinical and pathologic findings; and (3) the relationship of pathologic findings to respiratory health, especially those involving small airways.