1. Department of Earth and Environmental Sciences, California State University East Bay, Hayward, California 94542, United States
2. Department of Geography, University of California, Los Angeles, Los Angeles, California 90095, United States
3. Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, Berkeley, California 94720, United States
4. Department of Epidemiology and Biostatistics, School of Medicine, University of California, San Francisco, San Francisco, California 94158, United States