1. Department of Population Medicine, Harvard Pilgrim Health Care Institute and Harvard Medical School, Boston, Massachusetts, USA
2. Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA
3. Section of Biostatistics and Epidemiology, Department of Community and Family Medicine, Dartmouth Medical School, Lebanon, New Hampshire, USA
4. Washington State Department of Health, Olympia, Washington, USA
5. Laboratoire d’economie des ressources naturelles, Institut national de la recherche agronomique, Toulouse School of Economics, Toulouse, France
6. U.S. Environmental Protection Agency, Washington, DC, USA
7. Channing Laboratory, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, USA