1. Department of Medicine, Division of Respiratory Medicine The University of British Columbia Vancouver British Columbia Canada
2. Department of Pulmonary, Critical Care & Sleep Medicine Yale University New Haven Connecticut USA
3. Department of Medicine University of Maryland Baltimore Maryland USA
4. Department of Medicine, Division of Environmental & Occupational Health Sciences, National Jewish Health University of Colorado Denver Denver Colorado USA
5. Denver Health and Hospital Authority Denver Public Health Denver Colorado USA
6. Occupational & Environmental Health Division, University Health Network University of Toronto Toronto Ontario Canada
7. Occupational and Environmental Medicine Division, School of Public Health and Community Medicine, Sahlgrenska Academy University of Gothenburg Gothenburg Sweden
8. Department of Occupational and Environmental Medicine Sahlgrenska University Hospital Gothenburg Sweden
9. Division of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, School of Medicine University of New Mexico Albuquerque New Mexico USA
10. Division of Occupational and Environmental Medicine Icahn School of Medicine at Mount Sinai New York New York USA