1. National Center for Health Statistics, Centers for Disease Control and Prevention, Hyattsville, MD, USA
2. National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
3. Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, College Park, Maryland, USA
4. Research Triangle Institute, Research Triangle Park, NC, USA
5. The Orkand Corporation, Falls Church, Virginia, USA
6. The Office of Science Coordination and Policy, Office of Prevention, Pesticides, and Toxic Substances, U.S. Environmental Protection Agency, Washington, DC, USA