1. Department of Pediatrics, Korea University Anam Hospital, Seoul, Korea.
2. Graduate School of Social Welfare, Yonsei University, Seoul, Korea.
3. Department of Urban Planning and Engineering, Yonsei University, Seoul, Korea.
4. Department of Environmental Science and Ecological Engineering, Korea University, Seoul, Korea.
5. School of Civil and Environmental Engineering, Korea University, Seoul, Korea.
6. Department of Pediatrics, Korea University College of Medicine, Seoul, Korea.