1 Child Health Advocacy Institute, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
2 Department of Developmental and Behavioral Pediatrics, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
3 Department of Epidemiology, University of California Los Angeles, Los Angeles, CA, USA.
4 Department of Health Policy and Management, College of Public Health, University of Georgia, Athens, GA, USA.
5 Preschool Education Committee, Chinese Society of Education, Shanghai, China.
6 Department of Preschool Education Information, Information Center, Shanghai Municipal Education Commission, Shanghai, China.
7 Department of Basic Education, Shanghai Municipal Education Commission, Shanghai, China.
8 Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Shanghai, China.