1. Department of Thoracic Surgery, University Hospital Regensburg, 93053 Regensburg, Germany
2. Institute and Clinic for Occupational, Social and Environmental Medicine, University Hospital, LMU Munich, 80539 Munich, Germany
3. Comprehensive Pneumology Center Munich, German Center for Lung Research, 81377 Munich, Germany
4. Department of Thoracic Surgery, Hospital Barmherzige Brueder, 93047 Regensburg, Germany