Affiliation: | 1. Department of Occupational and Environmental Medicine, Seegene Medical Foundation, Seoul, Korea;2. Department of Occupational and Environmental Medicine, Hallym University Sacred Heart Hospital, Seoul, Korea;3. Department of Occupational and Environmental Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, South Korea;4. Department of Occupational Medicine, Graduate School of Public Health, School of medicine, the Catholic University of Korea, Seoul, Korea |