1. Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University, Taipei, Taiwan;
2. Graduate Institute of Public Health, Taipei Medical University, Taipei, Taiwan;
3. Graduate Institute of Environmental Engineering, National Central University, Jhongli, Taoyuan, Taiwan;
4. Department of Otolaryngology, Buddhist Tzuchi General Hospital, Taichung Branch, Taichung, Taiwan;
5. School of Medicine, Tzuchi University, Hualien, Taiwan;
6. Division of Biostatistics and Bioinformatics, Institute of Population Health Sciences, Zhunan, Miaoli, National Health Research Institutes; and
7. Department of Environmental and Occupational Medicine, National Taiwan University College of Medicine and National Taiwan University Hospital, Taipei, Taiwan