1. Occupational Diseases Clinic, Ankara Gazi Mustafa Kemal Occupational and Environmental Diseases Hospital, Ankara, Turkey
2. Occupational Diseases Clinic, Mersin City Training and Research Hospital, Mersin, Turkey
3. Occupational Diseases Clinic, Ankara Kecioren Sanatorium Ataturk Chest Diseases and Thoracic Surgery Training and Research Hospital, Ankara, Turkey
4. Department of Radiology, Hacettepe University, Ankara, Turkey
5. Department of Chest Diseases, Hacettepe University, Ankara, Turkey