1. Respiratory Epidemiology and Public Health Group; National Heart and Lung Institute; Imperial College London; London UK
2. Department of Experimental Immunology; Academic Medical Center; University of Amsterdam; Amsterdam the Netherlands
3. Department of Otorhinolaryngology; Academic Medical Center; University of Amsterdam; Amsterdam the Netherlands
4. Occupational and Environmental Medicine; Umeå University; Umeå Sweden
5. Department of Medical Sciences: Respiratory Medicine and Allergology; University of Uppsala; Uppsala Sweden
6. Krefting Research Centre; Institute of Medicine; University of Gothenburg; Gothenburg Sweden
7. CfA - The Centre for Allergy Research; Karolinska Institutet; Stockholm Sweden
8. Skin and Allergy Hospital; Helsinki University; Helsinki Finland
9. Department of ORL-HNS; Temple University; Philadelphia PA USA
10. Department of Occupational and Environmental Medicine; Odense Patient Extended Network; Odense University Hospital; Odense University; Odense Denmark
11. Department of Epidemiology; Medical University of Silesia in Katowice; Katowice Poland
12. Department of Medicine; Jagiellonian University Medical College; Krakow Poland
13. Department of Immunology, Rheumatology and Allergy; Medical University of Lodz; Lodz Poland
14. Clinical and Experimental Sciences; Faculty of Medicine; University of Southampton; Southampton UK
15. Academic Medical Center; Amsterdam the Netherlands
16. Upper Airways Research Laboratory; University of Ghent; Ghent Belgium
17. Division of Ear, Nose, and Throat Diseases, Clintec; Karolinska Institutet; Stockholm Sweden
18. Institute of Social Medicine, Epidemiology and Health Economics; Charité - Universitätsmedizin Berlin; Berlin Germany
19. Institute of Clinical Epidemiology and Biometry; University of Würzburg; Würzburg Germany
20. IUF - Leibniz Research Institute for Environmental Medicine; Düsseldorf Germany
21. Department of Dermatology and Allergy am Biederstein; Technical University Munich; Munich Germany
22. Institute for Occupational Health of Republic of Macedonia; Skopje Macedonia
23. Institute of Biomedicine and Molecular Immunology; National Research Council; Palermo Italy
24. Faculty of Medicine; University of Coimbra; Coimbra Portugal
25. MRC-PHE Centre for Environment and Health; Imperial College; London UK