1. San Francisco Veterans Affairs Medical Center, San Francisco, California
2. Department of Medicine, University of California at San Francisco, San Francisco, California
3. Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California
4. Department of Medicine
5. Department of Environmental Medicine, and
6. Department of Medicine and
7. Center for Environmental Medicine, Asthma and Lung Biology, University of North Carolina, Chapel Hill, North Carolina
8. Department of Public Health Sciences, University of Rochester Medical Center, Rochester, New York
9. New England Research Institute, Watertown, Massachusetts; and
10. Department of Pediatrics, School of Medicine, and
11. Health Effects Institute, Boston, Massachusetts