1. Centers for Disease Control and PreventionNational Center on Birth Defects and Developmental Disabilities Atlanta Georgia
2. Colorado Department of Public Health & Environment Denver Colorado
3. RTI International Atlanta Georgia
4. Weill Cornell Medical College New York New York
5. Bureau of Environmental and Occupational EpidemiologyNew York State Department of Health Albany New York
6. University of Colorado, Denver and Children's Hospital Aurora Colorado
7. Department of Epidemiology, College of Public HealthUniversity of Iowa Iowa City Iowa