1. Department of Pediatrics, University of Ulsan College of Medicine, Ulsan University Hospital, Ulsan, Korea.
2. Department of Occupational and Environmental Medicine, Dongguk University-Seoul, Graduate School of Medicine, Dongguk University Ilsan Hospital, Goyang, Korea.
3. Department of Preventive Medicine, School of Medicine, Ewha Womans University, Seoul, Korea.
4. Medical Research Institute, Ewha Global Challenge Center, Ewha Womans University, Seoul, Korea.
5. Department of Preventive Medicine, Dankook University College of Medicine, Cheonan, Korea.
6. Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Korea.
7. Department of Obstetrics and Gynecology, University of Ulsan College of Medicine, Ulsan University Hospital, Ulsan, Korea.
8. Department of Laboratory Medicine, University of Ulsan College of Medicine, Ulsan University Hospital, Ulsan, Korea.
9. Department of Occupational and Environmental Medicine, University of Ulsan College of Medicine, Ulsan University Hospital, Ulsan, Korea.