1. Columbia Center for Children's Environmental Health, Mailman School of Public Health, Columbia University, New York, New York, USA
2. Epidemiology and Preventive Medicine, College of Medicine, Jagiellonian University, Krakow, Poland
3. Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA
4. Department of Analytical and Environmental Chemistry, Southwest Research Institute, San Antonio, Texas USA
5. Department of Biostatistics, Mailman School of Public Health, Columbia University, New York, New York, USA
6. Department of Statistics, National Cheng Kung University, Taiwan