1. Department of Otolaryngology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
2. Department of Environmental and Occupational Health, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
3. Department of Otolaryngology, Tainan Hospital, Ministry of Health and Welfare, Tainan, Taiwan
4. Department of Occupational Safety and Health, College of Public Health, China Medical University, Taichung, Taiwan
5. Institute of Labor, Occupational Safety and Health, Ministry of Labor, Executive Yuan, New Taipei, Taiwan
6. Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Miaoli, Taiwan
7. Department of Occupational Safety and Health, Chang Jung Christian University, Tainan, Taiwan
8. Department of Public Health, College of Public Health, China Medical University, Taichung, Taiwan
9. Department of Health Risk Management, College of Public Health, China Medical University, Taichung, Taiwan