1. Public Health Ontario, Toronto, ON M5G 1V2, Canada
2. ICES, Toronto, ON M4N 3M5, Canada
3. Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, QC H3A 0G4, Canada
4. Air Health Science Division, Health Canada, Ottawa, ON K1A 0K9, Canada
5. Dalla Lana School of Public Health, University of Toronto, Toronto, ON M5S 1A1, Canada
6. Department of Family and Community Medicine, University of Toronto, Toronto, ON M5S 1A1, Canada
7. Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON K1A 0K9, Canada
8. Department of Civil and Mineral Engineering, University of Toronto, Toronto, ON ON M5S, Canada
9. School of Public Health, University of California Los Angeles, Los Angeles, California 90095, United States
10. Department of Physics and Atmospheric Science, Dalhousie University, Halifax, NS B3H 4R2, Canada
11. Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130, United States
12. Harvard-Smithsonian Centre for Astrophysics, Cambridge, Massachusetts 02138, United States
13. Department of Chemistry, University of California Irvine, Irvine, California 92697, United States