1. Department of Public Health, Section for Environment, Occupation and Health, Danish Ramazzini Centre, Aarhus University, Aarhus, Denmark
2. Department of Medical Sciences: Respiratory, Allergy and Sleep Research, Uppsala University, Uppsala, Sweden
3. Faculty of Medicine, University of Iceland, Reykjavik, Iceland
4. Division of Occupational and Environmental Medicine, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
5. Department of Occupational and Environmental Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden
6. Lung Clinic, Tartu University Hospital, Tartu, Estonia
7. Centre for Clinical Research, Haukeland University Hospital, Bergen, Norway
8. Centre for International Health, Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
9. Department of Occupational Medicine, Haukeland University Hospital, Bergen, Norway
10. National Research Centre for the Working Environment, Copenhagen, Denmark