a Department of Respiratory Medicine, University Hospital Olomouc and Faculty of Medicine and Dentistry, Palacky University Olomouc,
Czech Republic
bDepartment of Occupational Medicine, General University Hospital in Prague and 1st Faculty of Medicine, Charles University in Prague
cDepartment of Occupational Medicine, University Hospital Olomouc and Faculty of Medicine and Dentistry, Palacky University Olomouc
Corresponding author: Petr Jakubec, e-mail: jakubecp@fnol.cz