1. Department of Pediatrics, Gwangmyeong Sungae Hospital, Gwangmyeong, Korea.
2. Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
3. Environmental Health Center for Atopic Diseases, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
4. Department of Social and Preventive Medicine, Sungkyunkwan University School of Medicine, Suwon, Korea.
5. Seoul Research Institute of Public Health & Environment, Seoul, Korea.