1. Department of Occupational Medicine, University Hospital Olomouc and Faculty of Medicine and Dentistry, Palacký University Olomouc , Olomouc, Czech Republic
2. Department of Public Health Protection, Ministry of Health of the Czech Republic , Prague, Czech Republic
3. Department of Public Health, Faculty of Medicine and Dentistry, Palacký University Olomouc , Olomouc, Czech Republic