1. Department of Occupational and Environmental Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
2. Total Healthcare Centre, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
3. Industrial Health and Work Environment Research Institute, Korean Industrial Health Association, Seoul, Republic of Korea
4. Department of Occupational and Environmental Medicine, Wonju Severance Christian Hospital, Wonju, Republic of Korea
5. Department of Occupational and Environmental Medicine, Keimyung University School of Medicine, Daegu, Republic of Korea
6. Department of Preventive Medicine, Wonju College of medicine, Yonsei University, Wonju, Republic of Korea