1. Office of Health Research, U.S. Environmental Protection Agency Washington, DC
2. Environmental Health Service, Rancho Los Amigos Medical Center Downey, CA
3. McGill University, Faculty of Medicine Montreal, Canada
4. Columbia University, Harlem Hospital Department of Medicine New York, NY
5. Channing Laboratory, Brigham and Women's Hospital Boston, MA
6. New Mexico Tumor Registry, The University of New Mexico Medical Center Albuquerque, NM
7. Pulmonary Disease Unit, University of Rochester Medical Center Rochester, NY