1. University of Texas School of Public Health, Dallas, Texas, USA
2. National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC, USA
3. Wadsworth Center, New York State Department of Health, Albany, New York, USA
4. Department of Environmental Health Sciences, State University of New York at Albany, Albany, New York, USA
5. University of Texas Southwestern Medical Center, Dallas, Texas, USA
6. University of Michigan, Ann Arbor, Michigan, USA
7. National Cancer Institute, and
8. National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA