1. Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, M5S 3E5
2. Department of Geography, University of Toronto, Toronto, Ontario, M5S 3G3
3. Current address: Environmental Monitoring and Reporting Branch, Ontario Ministry of the Environment, 125 Resources Road, Toronto, Ontario M9P 3V6
4. Current address: Ontario Agency for Health Protection and Promotion, 480 University Avenue, Suite 300, Toronto, Ontario M5A 4H8