1. Epidemiology Branch, National Institute of Environmental Health Sciences, NIH, Research Triangle Park NC
2. Biostatistics BranchNational Institute of Environmental Health Sciences, NIH, Research Triangle Park NC
3. Social & Scientific SystemsDurham NC
4. Division of Cancer Epidemiology and GeneticsMetabolic Epidemiology Branch, National Cancer Institute, NIHBethesda MD
5. Department of EpidemiologyUniversity of North CarolinaChapel Hill NC