1. Exposure, Epidemiology, and Risk Program, Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA
2. U.S. Food and Drug Administration, Southeast Regional Laboratory, Atlanta, Georgia, USA (retired)
3. Department of Environmental and Occupational Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
4. U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, Maryland, USA