1. Department of Health Care Management, University of Kang Ning, 188 Anjhong Road, Section 5, Tainan 70970, Taiwan
2. Center for Occupational and Environmental Health and Preventive Medicine, National Cheng Kung University, 138 Sheng-Li Road, Tainan 70428, Taiwan
3. Department of Environmental and Occupational Health, College of Medicine, National Cheng Kung University, 138 Sheng-Li Road, Tainan 70428, Taiwan
4. Department of Occupational and Environmental Medicine, National Cheng Kung University Hospital, 138 Sheng-Li Road, Tainan 70428, Taiwan