1. Metabolic Epidemiology Branch, Division of Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland
2. Office of Science, Center for Tobacco Products Food and Drug Administration, Silver Spring, Maryland
3. United States Census Bureau, Suitland, Maryland
4. Tobacco Control Research Branch, Behavioral Research Program, Division of Cancer Control and Population Sciences, National Cancer Institute, National Institutes of Health, Bethesda, Maryland