1. School of Public Health, San Diego State University, San Diego, California 92182, United States
2. San Diego State University Research Foundation, San Diego, California 92182, United States
3. Enthalpy Analytical (formerly Nautilus Environmental), San Diego, California 92120, United States
4. School of Medicine, Division of Occupational and Environmental Medicine, University of California San Francisco, San Francisco, California 94143, United States