1. Department of Epidemiology University of North Carolina Gillings School of Global Public Health Chapel Hill North Carolina
2. Division of Cancer Prevention and Control Centers for Disease Control and Prevention Atlanta Georgia
3. Epidemiology Branch National Institute of Environmental Health SciencesNational Institutes of Health Research Triangle Park North Carolina
4. Social and Scientific Systems, Inc Durham North Carolina
5. Biostatistics and Computational Biology Branch National Institute of Environmental Health SciencesNational Institutes of Health Research Triangle Park North Carolina