1. School of Public Health, University of California, Berkeley, California 94720-7360;,
2. Department of Public Health and Policy, University of Liverpool, Liverpool, L69 3GB, United Kingdom;, ,
3. Department of Environmental Health Engineering, Sri Ramachandra University (SRU), Chennai 600116, India;
4. Pulmonary Medicine, University of California, San Francisco, California 94143;
5. Energy and Resources Group, University of California, Berkeley, California 94720-3050;
6. Division of Epidemiology, Albert Einstein College of Medicine, Bronx, New York 10461;
7. Global Alliance for Clean Cookstoves, Washington, DC 20006;
8. Department of Medical Informatics, Biometry and Epidemiology, University of Munich, Munich 81377, Germany;