1 Department of Occupational and Environmental Medicine, Pusan National University, Yangsan Hospital, Yangsan, Korea ; Department of Preventive and Occupational Medicine, Pusan National University, School of Medicine, Yangsan, Gyongnam, Korea.
2 Occupational Safety & Health Research Institute, Korea Occupational Safety & Health Agency, Ulsan, Korea.
3 Department of Occupational and Environmental Medicine, Haeundae Paik Hospital, Inje University, Busan, Korea.
4 Department of Occupational and Environmental Health, Yonsei University Graduate School of Public Health, Seoul, Korea.
5 Department of Occupational and Environmental Medicine, College of Medicine, the Catholic University, Seoul, Korea.
6 Department of Occupational and Environmental Medicine, Ajou University School of Medicine, Suwon, Korea.
7 Department of Preventive Medicine, Ewha Womans University School of Medicine, Seoul, Korea.
8 Department of Occupational and Environmental Medicine, Wonju Severance Christian Hospital, Wonju College of Medicine, Yonsei University, Wonju, Korea.
9 Department of Occupational and Environmental Medicine, Wonju Severance Christian Hospital, Wonju College of Medicine, Yonsei University, Wonju, Korea ; Department of Preventive Medicine and Institute of Occupational and Environmental Medicine, Wonju College of Medicine, Yonsei University, Wonju, Korea.