1. Department of Environmental & Occupational Health Sciences, University of Washington, Seattle, WA, USA
2. Comite Civico del Valle, Brawley, CA, USA
3. California Environmental Health Tracking Program, Richmond, CA, USA
4. Department of Environmental and Occupational Health, George Washington University, Washington, DC, USA
5. Department of Environmental Health Sciences, University of California, Los Angeles, CA, USA
6. Monitoring and Laboratory Division, California Air Resources Board, Sacramento, CA, USA