1 Health Canada, Environmental and Radiation Health Sciences Directorate, Consumer and Clinical Radiation Protection Bureau, 775 Brookfield Road, Ottawa, Ontario K1A 1C1, Canada.
2 Health Canada, Population Studies Division, Biostatistics Section, 200 Eglantine Driveway, Tunney's Pasture, Ottawa, Ontario, Canada.
3 Health Canada, Environmental Health Program, Health Programs Branch, Regions and Programs Bureau, 1505 Barrington Street, Halifax, Nova Scotia, Canada.
4 Health Canada, Environmental and Radiation Health Sciences Directorate, Office of Science Policy, Liaison and Coordination, 269 Laurier Avenue West, Ottawa, Ontario, Canada.
5 Health Canada, Air Health Science Division, 269 Laurier Avenue West, Ottawa, Ontario, Canada.
6 Department of Medicine, Division of Neurology, Sunnybrook Health Sciences Center, University of Toronto, Toronto, Ontario, Canada.
7 Department of Pediatrics, Division of Neurology, Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, Ontario, Canada.
8 The Amsterdam Public Health Service (GGD Amsterdam), Environmental Health Department, Nieuwe Achtergracht 100, Amsterdam, The Netherlands.