1. Department of Community Health Services, Denver Health, Denver, Colorado, USA
2. Department of Pediatrics, University of Colorado Health Science Center, Denver, Colorado, USA
3. Association of Occupational and Environmental Clinics, Washington, DC, USA
4. Department of Environmental and Occupational Health, Mid-Atlantic Center for Child Health and the Environment, School of Public Health and Health Sciences, George Washington University Medical Center, Washington, DC
5. Departments of Medicine/Preventive Medicine and Biometrics, National Jewish Medical and Research Center, Denver, Colorado, USA