1. Ewha Womans University College of Medicine, Seoul, Korea.
2. Department of Pediatrics, Ewha Womans University College of Medicine, Seoul, Korea.
3. Department of Occupational and Environmental Medicine, Hallym University Sacred Heart Hospital, Anyang, Korea.
4. Department of International Studies, Graduate School of International Studies, Ewha Womans University, Seoul, Korea.
5. Department of Occupational and Environment Medicine, Ewha Womans University College of Medicine, Seoul, Korea.