1. Institute for Prevention and Occupational Medicine of the German Social Accident Insurance; Ruhr-University Bochum (IPA); Bochum; Germany
2. Department of Chest Diseases; University Hospital Strasbourg; Strasbourg; France
3. Occupational Medicine; Terni Hospital; University of Perugia; Perugia; Italy
4. Austrian workers compensation board; Rehabilitation Clinic Tobelbad; Tobelbad; Austria
5. Allergy and Immunology Unit; Fondazione ‘Salvatore Maugeri’; Institute of Research and Care; Scientific Institute of Pavia; Pavia; Italy
6. Unit of Occupational Medicine; University Hospital of Verona; Verona; Italy
7. Department of Allergy; Hospital La Paz (IdiPAZ) and CIBER of Respiratory Diseases CIBERES; Madrid; Spain
8. Department of Allergy; Fundación Jiménez Díaz and CIBER of Respiratory Diseases CIBERES; Madrid; Spain
9. Nofer Institute of Occupational Medicine; Lodz; Poland