1. Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, California 94720, United States
2. Department of Chemical and Environmental Engineering and College of Engineering-Center for Environmental Research and Technology, University of California, Riverside, Riverside, California 92507, United States
3. Aerosol Dynamics Inc., Berkeley, California 94710, United States
4. Department of Civil and Environmental Engineering, University of California, Berkeley, Berkeley, California 94720, United States