1. Department of Pulmonary Diseases, Ataturk University, School of Medicine , Erzurum , Turkey
2. University of Health Sciences, Süreyyapasa Chest Diseases and Thoracic Surgery Training and Research Hospital , Istanbul , Turkey
3. Adana Research and Training Hospital, Division of Occupational Health and Occupational Diseases , Adana , Turkey
4. Akkurt Coal Mining Company , Zonguldak , Turkey
5. Department of Pulmonary Diseases, Düzce University, School of Medicine , Düzce , Turkey
6. Retired Pulmonary Physician, Occupational Diseases Specialist , Ankara , Turkey