1. Department of Occupational Medicine, Buddhist Tzu Chi General Hospital, No. 707, Section 3, Jhongyang Road, Hualien 97002, Taiwan
2. School of Medicine, Tzu Chi University, No. 701, Section 3, Jhongyang Road, Hualien 97004, Taiwan
3. Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University College of Public Health, No. 17 Xuzhou Road, Taipei 100, Taiwan
4. Department of Environmental and Occupational Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, No. 1 Jen Ai Road, Section 1, Taipei 100, Taiwan
5. Department of Public Health, College of Medicine, National Cheng Kung University, No. 1, University Road, Tainan 701, Taiwan
6. Departments of Internal Medicine and Occupational and Environmental Medicine, National Cheng Kung University Hospital, No. 138, Sheng Li Road, Tainan 704, Taiwan