1. Department of Epidemiology, Faculty of Public Health in Bytom, Silesian Medical University in Katowice, 41-902 Bytom, Poland
2. Department of Laryngology, Faculty of Medical Sciences, Silesian Medical University in Katowice, 40-055 Katowice, Poland
3. Department of Sports Tourism, Faculty of Physical Culture Sciences, Poznan University of Physical Education, 61-871 Poznan, Poland
4. Department of Public Health, Faculty of Public Health in Bytom, Silesian Medical University in Katowice, 41-902 Bytom, Poland