1. Epidemiology Branch and
2. Department of Biological Sciences, Center for Human Health and the Environment, North Carolina State University, Raleigh, North Carolina
3. Department of Occupational and Environmental Health, University of Iowa, Iowa City, Iowa
4. Hankinson Consulting, Inc., Athens, Georgia
5. Social & Scientific Systems, Inc., Durham, North Carolina
6. Westat, Durham, North Carolina
7. Occupational and Environmental Epidemiology Branch, National Cancer Institute, Bethesda, Maryland; and
8. Respiratory Health Division, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Department of Health and Human Services, Morgantown, West Virginia
9. Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina