1. Department of Health Management, I-Shou University, Kaohsiung, Taiwan
2. Department of Safety, Health and Environmental Engineering, National Kaohsiung First University of Science and Technology, Kaohsiung, Taiwan
3. Department of Environmental Engineering, College of Engineering, Chung Yuan Christian University, Chung Li, Taiwan
4. Department of Public Health, China Medical University, Taichung, Taiwan
5. Department of Internal Medicine, Divisions of Pulmonary and Critical Care Medicine, China Medical University Hospital, Taichung, Taiwan
6. School of Medicine, China Medical University, Taichung, Taiwan