1. School of Community and Environmental Health, College of Health Sciences, Old Dominion University, Norfolk, Virginia, USA;
2. Department of Occupational Medicine, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan;
3. Department of Occupational Safety and Health, Chung Shan Medical University, Taichung, Taiwan;
4. Institute of Occupational Safety and Health, Council of Labor Affairs, Executive Yuan, Taipei, Taiwan