1. Department of Chest Medicine; Centre Hospitalier Universitaire de Mont-Godinne; Université Catholique de Louvain; Yvoir Belgium
2. Department of Occupational Diseases and Clinical Toxicology; Nofer Institute of Occupational Medicine; Lodz Poland
3. IPA Institute for Prevention and Occupational Medicine of the German Social Accident Insurance; Institute of the Ruhr-Universität Bochum; Bochum Germany
4. Division of Asthma and Allergy; Department of Chest Diseases; University Hospital; Fédération de Médecine Translationnelle de Strasbourg; Strasbourg University; Strasbourg France
5. Section of Allergology; Department of Internal Medicine; Erasmus MC; Rotterdam The Netherlands
6. Department of Public Health; Experimental and Forensic Medicine of the University of Pavia; Pavia Italy
7. Department of Public Health and Primary Care; KU Leuven; Leuven Belgium
8. Occupational Physician's Division; Local Health Authority of Sassari; Sassari Italy
9. Department of Allergy; Hospital La Paz Institute for Health Research (IdiPAZ); CIBER de Enfermedades Respiratorias (CIBERES); Madrid Spain
10. Department of Allergy; Fundación Jiménez Díaz; CIBER de Enfermedades Respiratorias (CIBERES); Madrid Spain
11. Section of Environment, Occupation and Health; Department of Public Health; University of Aarhus; Aarhus Denmark
12. Formerly Department of Clinical and Experimental Medicine; University of Perugia; Perugia Italy
13. Department of Medicine and Dalla Lana School of Public Health; University of Toronto; Toronto ON Canada
14. Respiratory Division; Toronto Western Hospital; Toronto ON Canada
15. Gage Occupational and Environmental Health Unit; St Michael's Hospital; Toronto ON Canada
16. Centre for Research in Environmental Epidemiology (CREAL); Barcelona Spain
17. Universitat Pompeu Fabra (UPF); Barcelona Spain
18. Centro de Investigación Biomédica en Red en Epidemiología y Salud Pública (CIBERESP); Madrid Spain
19. Netherlands Institute of Health Services Research (NIVEL); Utrecht the Netherlands