There is still time to address aerosol transmission of COVID-19 January 4, 2020 Dear Dr. Theresa Tam, Hon. Patty Hajdu, Premiers and Medical Officers, We are a group of physicians, scientists, occupational health and safety experts, engineers and nursing professionals who have been following the COVID-19 developments closely. We are deeply concerned by the recent increase in cases and hospitalizations across Canada. We urge you to update the provincial COVID-19 guidelines, workplace regulations and public communication to reflect the science – COVID-19 spreads through inhaled aerosols. In July of 2020, 239 international scientists brought this issue to the world stage1 . Since the publication of their letter, some progress has been made gaining recognition from the World Health Organization, Centre for Disease Control and Public Health Agency of Canada for aerosol transmission of COVID192 . However, this has not resulted in any significant improvement in workplace protection for Health Care Workers (HCWs) and other essential workers. There also continues to be a lack of public messaging at the provincial level to reflect the risk of transmission in shared room air. While other countries promote avoiding the 3 C’s (closed spaces, crowded places and close-contact settings), we continue to focus on deep-cleaning and two-metre physical distancing. With winter upon us, our activities are moving indoors and it is therefore imperative that workplaces, public institutions and individuals understand the risk of aerosol transmission as well as the actions that can be taken to combat it. The rapid global spread of COVID-19 has sparked unprecedented cross-disciplinary research. Contributions from the fields of engineering, life science, aerosol science, medicine, occupational hygiene and epidemiology are driving a paradigm shift in our understanding of aerosol transmission of respiratory viruses, including COVID-19. The evidence is now overwhelming - aerosol transmission of COVID-19 is common and is an important route of transmission.3-6 This was elegantly summarized by Fang et al: "perhaps the biggest surprise about the issue of airborne spread of SARS-CoV2 is that it has been surprising to so many people".4 Virus-laden aerosols frequently infect susceptible contacts at close proximity where they are most concentrated – like smoke. In suboptimally ventilated environments, infectious aerosols can accumulate in shared room air and reach dangerous concentrations. Control strategies targeting close-proximity transmission, such as physical distancing and effective face-fitted masks, are key to reduce short-range aerosol transmission risk. For transmission in shared room air, ventilation and air filtration are critical additional measures, as expelled aerosols build up in poorly ventilated spaces. We know that many workplaces, buildings and residences in our communities have substandard ventilation. With this evolving science, the importance of monitoring and improving ventilation has become increasingly clear. The September 28, 2020 report by Canada’s Chief Science Advisor Expert Panel on COVID-19 summarizes high-yield short-term and long-term goals to reduce indoor transmission of COVID-19 and improve indoor air quality.7 Despite this report, there continues to be a lack of attention to the importance of ventilation at the provincial and federal levels. The acknowledgement of aerosol transmission also calls into question the provincial directives for personal protective equipment for HCWs and other essential workers. Most HCWs and essential workers in Canada continue to use “droplet and contact precautions”, wearing poorly-fitted surgical masks, even in high-risk settings. A letter from the Workplace Health Without Borders international board of directors to Dr. Theresa Tam in April 2020 highlights these concerns well.8 To reflect the current scientific evidence, we call on provincial leaders to: ❖ Update COVID-19 guidance to address the risk of aerosol transmission of COVID-19 ❖ Promote strategies to reduce transmission risk in private homes and businesses through clear public health messaging and education o Avoid the “3 C’s”, indoor mask wearing even when distanced, routinely opening windows to refresh the air, regular HVAC maintenance and filter replacement, turning on available vented range hoods and bathroom exhaust fans ❖ Mandate and fund ventilation assessments and upgrades of essential public institutions such as schools and long-term care homes ❖ Ensure that no high risk healthcare worker (HCW) or other essential worker is denied access to a fit-tested respirator (N95, elastomeric or equivalent) o Risk assessment by HCWs should go beyond the presence of “aerosol generating procedures” and should take into consideration aerosol generating behaviours (ie. shouting, singing, coughing, sneezing, heavy breathing), proximity to the patient, time spent with the patient, building air quality, and patient compliance with masking for source control o Risk assessment for other essential workers should consider crowding, close contact, presence of aerosol generating behaviours, and building air quality ❖ Recommend and deploy carbon dioxide (CO2) monitors as a surrogate measure of inadequate ventilation to reduce long-range transmission risk in shared room air o During a TB outbreak, CO2 concentrations above 1000 PPM significantly increased the risk of becoming infected with TB.9 Improving the building ventilation to a CO2 concentration of 600 PPM stopped the outbreak in its tracks. ❖ Include appropriately sized portable air filtration (HEPA) units or low-cost homemade devices using MERV-11/13 filters and box fans as options for filtering out bioaerosols indoors when ventilation is suboptimal ❖ Engage engineers and other ventilation specialists to develop clear ventilation standards for indoor institutions and integrate these standards into the reopening guidelines for businesses with a higher risk of aerosol transmission (e.g. restaurants, bars and gyms) Specific strategies to reduce indoor aerosol transmission of COVID-19 are adeptly summarized in Canada’s Chief Science Advisor Expert Panel on COVID-19 bioaerosol report7 , the Occupational Safety and Health Administration (OSHA) Alert10, the Harvard TC Chan Risk Reduction Strategies for Reopening Schools Report11, the CDC’s “COVID-19 Ventilation in Buildings” guidance12, the European CDC’s “Heating, Ventilation and Air-conditioning Systems in the Context of COVID-19: First Update”13, and the “ASHRAE Position Document on Infectious Aerosols”14. Experts warn that future respiratory viral pandemics are likely.15 Investing in ventilation, indoor air quality and appropriate personal protective equipment now will save lives and prevent economic hardship in the future. Germany is investing €500m to improve ventilation systems in public buildings. 16 China implemented airborne precautions for HCWs in January 2020. Italy, New Zealand, and Japan have all accepted and promote aerosol messaging. The public health “sanitary reformers” of the late 1800s led the way in overcoming water-borne diseases like cholera and typhoid fever through investments in sewer systems and water treatment plants.17 We are certain that there were those who thought the task at hand was insurmountable. When the history of Canada’s response to COVID-19 is written, we hope that our country is once again viewed as a public health innovator. Disclaimer: The views and opinions expressed in this letter are those of the individual signatories and do not necessarily reflect the official policy or position of any agency/institution. Supporting Signatures from Canadian Experts in Aerosols, Indoor Air Quality, Epidemiology and/or Infectious Diseases: Physicians Name Credentials and Affiliations City Province Raidan Alyazidi MBBS, MSc, FRCPC Pediatrics/ Infectious diseases Montreal QC Joel Andersen MD, MSc,CFPC,FCBOM,CIME Occupational Medicine Sudbury ON David Fisman MD MPH FRCP(C) Toronto ON Ted Haines MD Hamilton ON Anne A. Huang BScHon MD MSc CCFP Saskatoon SK Amir Khadir MD Microbiologie médicale-infectiologie Lachenaie QC Victor Leung MD FRCPC Vancouver BC Me-Linh Luong MD. Infectious disease specialist Montreal QC Christine Oliver MD, MPH, MS, Dalla Lana School of Public Health, University of Toronto Toronto ON Matthew Oughton MD Montréal QC Raymond Tellier MD MSc FRCPC CSPQ FCCM D(ABMM), Medical Microbiologist, Associate Professor McGill University Montreal QC Gerasimos J. Zaharatos MD, FRCPC, Infectious Disease specialist and Medical Microbiologist Montréal ON Scientists and Engineers Name Credentials and Affiliations City Province Andreas Athienitis Engineer, Professor and Director of Concordia Centre for Zero Energy Building Studies, Fellow of Canadian Academy of Engineering, Fellow of ASHRAE Brossard QC Stéphane Bilodeau Ingénieur, Ph.D., FIC, Encoronavirus.org Canada-Outreach, CovidSTOP, Zero Covid Canada Sherbrooke QC Michel Camus PhD / épidémiologiste Montréal QC Roxane Borgès Da Silva PhD en santé publique Montréal QC Maximilien Debia Ph.D., Associate Professor, School of Public Health, Université de Montréal Montréal QC Nicole Dedobbeleer Sc.D en santé publique Verdun QC Myrna B Dolovich PEng, Professor Medicine (part-time), McMaster University, Hamilton ON Firestone Institute for Respiratory Health, St Joseph's Hospital Caroline Duchaine PhD, holder, Canada Research Chair on Bioaerosols and Professor Université Laval Québec QC Warren Finlay PhD, PEng, Fellow Royal Society of Canada, Distinguished Professor Edmonton AB Brian Fleck Ph.D., P.Eng. Edmonton AB Michel Gagné MSc, BSc Chimie et chimie organique. CSA Member of Respiratory Protection Standard Committiees Z94.4 & Z180.1 Laval QC Hua Ge P. Eng. Building Engineering Richmond Hill ON Nimâ Machouf PhD in Public Health Montréal QC Genevieve Marchand Ph.D. Biochimiste et Microbiologiste agrée spécialisée en SST et Bioaérosols Montréal QC Andrew Martin PhD PEng Edmonton AB Richard Massicotte Ph.D Chercheur spécialisé en désinfection des milieux de soins Joliette QC Syed A. Sattar BSc, MSc, MS, Dip Bact, PhD Ottawa ON Theodore Stathopoulos Ing, Ph.D. in Engineering Montreal QC Ashleigh Tuite PhD MPH MSc Toronto ON Reinhard Vehring PhD, PEng, George Ford Chair at University of Alberta Edmonton AB Liangzhu (Leon) Wang PhD and PEng, Professor Concordia University Montreal QC Lexuan Zhong PhD, PEng Edmonton AB Radu Zmeureanu Ing., PhD. Montreal QC Occupational Health and Safety Scientists and Professionals Name Credentials and Affiliations City Province Paul Bozek BASc MEng MBA PEng CIH ROH. Associate Professor, University of Toronto Dalla Lana School of Public Health Toronto ON Alec Farquhar LLB, Occupational Health and Safety Consultant, former Director, Ontario Ministry of Labour Occupational Health and Safety Branch Toronto ON Kevin Hedges Ph.D,. COH, CIH. International Past President Workplace Health Without Borders (WHWB), Occupational Hygienist Ottawa ON Chun-Yip Hon M.Sc(A), PhD, CRSP, CIH Toronto ON Jean-François Lafrenière Ph.D. Microbiologiste Québec QC Marc-Andre Lavoie M.Sc. Chemistry, ROH, Current CRBOH President Dartmouth NS Jacques Lavoie MASc Montreal QC Rene Leblanc M.Sc., CRSP, ROH Montreal QC Michel Legris M. Sc Biologie et DOH Occupational Health Québec QC Marianne Levitsky MES, CIH, ROH, FAIHA Toronto ON Om Malik Engineer, Ph.D., CIH, ROH, FAIHA, QP Oakville ON John H. Murphy MHSc PhD ROH CIH MACE, Adjunct Professor - Dalla Lana School of Public Health, University of Toronto Toronto ON John Oudyk CIH, ROH, MSc, BASc, Assistant Professor McMaster University Hamilton ON Mario Possamai Senior Advisor, SARS Commission (2003-2007) Toronto ON James Scott PhD, ARMCCM Toronto ON Simon Smith PhD, CChem FRSC(UK), Chair, ISO working group for CBRN respirator standards, Chair, Canadian Standards Biological Aerosols Working Group Kingston ON Laurence Svirchev CIH, MA, BSc Vancouver BC Supporting Signatures from International Experts in Aerosols, Indoor Air Quality, Epidemiology and/or Infectious Diseases: Physicians Name Credentials and Affiliations City Country Stephanie Dancer MD, BSc, MSc, MRCPath, FRCP(Ed),DTM&H Glasgow UK Chandini Raina MacIntyre MBBS Hons1, M App Epid, PhD, FRACP, FAFPHM North Wahroonga Australia Julian W Tang PhD FRCPath, Clinical Virologist, Respiratory Sciences, University of Leicester Leicester UK Scientists and Engineers Name Credentials and Affiliations City Country William P. Bahnfleth PhD Mechanical Engineering, PE State College PA - USA Yaneer Bar-Yam PhD Physics Newton MA - USA Alex Huffman PhD atmospheric chemistry / aerosol science Denver CO - USA Jose-Luis Jimenez PhD in Mechanical Engineering, Massachusetts Institute of Technology, 1999. Currently Prof. of Chemistry and Fellow of CIRES, Univ. of Colorado-Boulder, USA Boulder CO - USA Linsey Marr Ph.D., Professor of Civil and Environmental Engineering, Virginia Tech Blacksburg VA - USA Shelly Miller PhD Boulder CO - USA William W Nazaroff PhD Oakland CA - USA Kim A Prather Ph.D. Chemistry, University of California, San Diego San Diego CA - USA Francesca Romana d'Ambrosio Full Professor of Building Physics, Department of Industrial Engineering, University of Salerno University of Salerno (Italy) Fisciano Italy Philomena M. Bluyssen Prof.dr. Delft Netherlands Atze Boerstra MSc Mechanical Engineering + PhD Building Sciences Rotterdam Netherlands Giorgio Buonanno Full professor, PhD, University of Cassino and Southern Lazio (Italy) Cassino Italy Francesco Franchimon PhD Berkel en Rodenrijs Netherlands Jacqueline Hamilton PhD in Chemistry. Professor of Atmospheric Chemistry, Wolfson Atmospheric Chemistry Laboratories, University of York. Vice President of the UK and Ireland Aerosol Society York UK Jaap Hogeling MASc Mechanical Engineering Lienden Netherlands Jarek Kurnitski Professor, Tallinn University of Technology, Aalto University, Chair REHVA Technology and Research Committee Tallinn Estonia Yuguo Li PhD Hong Kong Hong Kong Arsen K. Melikov PhD, Professor in Ventilation and Air Distribution, Technical University of Denmark l Kgs. Lyngby Denmark Asit Kumar Mishra PhD Limerick Ireland Lidia Morawska PhD Keperra Australia Xavier Querol Professor Barcelona Spain Kwok Wai Tham PhD SINGAPORE Singapore Pawel Wargocki PhD Kongens Lyngby Denmark Aneta Wierzbicka Associate Professor Lund Sweden Occupational Health and Safety Scientists Name Credentials and Affiliations City Country Susan Arnold PhD, CIH Minneapolis MN - USA Lisa M Brosseau ScD, CIH, Professor (retired), Research Consultant, University of Minnesota Center for Infectious Disease Research and Policy Minneapolis MN - USA David M. Zalk PhD, MPH, CIH San Jose CA - USA John Cherrie PhD Edinburgh UK Kate Cole BSc, MEEM, MSc, COH, CF, member of DHHS Victoria Infection Mechanisms Subgroup, member of National COVID-19 Clinical Evidence Taskforce ICEG/IPC Panel, AIOH President-Elect. Sydney Australia Brad Prezant MSPH, CIH, COH St Kilda East Australia Maosheng Yao Prof/PhD Beijing China Supporting Signatures from Canadian Physicians, Scientists, Occupational Health and Safety Professionals, Engineers and Nursing Professionals: Physicians Name Credentials and Affiliations City Province Leigh Beamish MD, BSc microbiology and immunology Hinton AB Keltie Duggan MD CCFP Calgary AB Christopher Ewing MD FRCPC Pediatrics and Pediatric Respirology Edmonton AB Christine Gibson MD CFPC MMedEd Calgary AB Tehseen Ladha MD, MPH, FRCPC Edmonton AB Faruqa Ladha MD FRCPC Calgary AB Linda L. Smith MD CCFP FCFP Edmonton AB Joe Vipond CCFP(EM), MD Calgary AB Nitin Wadhawan MD CCFP Calgary AB Rob Warren MD, CCFP Sundre AB Lisa Wilson MD CCFP Jasper AB Caroline Benedek MD, CCFP Vancouver BC James Heilman MD, CCFP(EM) Cranbrook BC Alexandre Henri￾Bhargava MDCM, MScCH, FRCPC Victoria BC Ainsley Sutherland MD, PhD, FRCPC North Vancouver BC Amy Tan MD MSc CCFP(PC) FCFP Victoria BC Giorgia Tropini MD, MSc Vancouver BC Anna Wolak MBBS, MCFP Vancouver BC Nicole Vosters MD Dauphin MB Amelia Barry MD FRCP Saint John NB Rachel Mallais MD, FRCPC Moncton NB Alison Power BMBS, CCFP, FCFP Moncton NB Mark Spurrell B. Eng (Mechanical Engineering), MD, FRCSC Grand Falls￾Windsor NL Nicole Herschenhous MD, FRCPC halifax NS Sarah Addleman MDCM, CCFP(EM) Ottawa ON Al Alipio Medical Doctor Hamilton ON Kelly Anderson CCFP(EM) Guelph/Eramosa ON Heather Badalato MD Oakville ON AbdulGhani Basith MD, CCFP (EM) Woodbridge ON Nicole Coles MD, FRCPC Toronto ON Shoshanah Deaton MD CCFP Ottawa ON Julianne Falconi Resident MD Toronto ON Brooks Fallis Critical Care Physician Toronto & Brampton ON Sarah Foohey MD, CCFP-EM Toronto ON Yoni Freedhoff Associate Professor, Dept. of Fam Med, University of Ottawa Ottawa ON Barry Gilbert MD FRCPC Toronto ON Anandita gokhale CFPC Kitchener ON Samantha Green MD, CCFP Toronto ON B. Harrison MD, CCFP Ottawa ON Ariel Hendin MD, FRCPC Ottawa ON Edith Hui MD CCFP Toronto ON Michael A. Hutcheon MD FRCPC Respirologist Toronto ON Wendy Iseman MD Toronto ON Jemy Joseph MD, CCFP Toronto ON Pravesh Jugnundan MD. FCFP. FCBOM. FACOEM. CIME. MRO (Occupational Medicine) Toronto ON Sabira Kanani MBChB CCFP Hamilton ON Magdie Kohn MD, FRCPC Brampton/Toron to ON Mark Kotowycz MD Barrie ON Jennifer Kwan MD CCFP Burlington ON Gabor Lantos P.Eng MBA MD Occupational Physician, Co-developer of NIOSH￾approved FitSeal FFPR's Toronto ON Christopher Leighton MD, FRCPC, Radiation Oncologist, Adjunct Professor, Department of Oncology, Schulich School of Medicine & Dentistry, Western University Windsor ON Neil Maharaj Respirologist, MD, FRCPC Niagara Falls ON Samantha Martin MD, FRCPC Toronto ON Jennifer McDonald MD, FRCPC PM&R Ottawa ON Ann Mills HBSc, MD, FRCPC Ajax ON Justin Morgenstern MD, MSc, CCFP(EM) Toronto ON Sailaja Nallapaneni MD. FRCSC Toronto ON Melanie Ostreicher MD FRCPC Toronto ON Philip Peng MBBS, FRCPC North York ON Kashif Pirzada MD, CCFP(EM) Toronto ON Jeffrey S Price MD London ON Aarthi Rajagopalan MBBS, FRCSC London ON Michael Roberts MD FCFP Toronto ON Brie-Anne Rosenberg MD Ottawa ON Faria Sakhia MBBS, CCFP, MPH Toronto ON Laura Shoots MD CCFP(EM) MSc QIPS Brantford ON Jenny Shu MD Toronto ON Vidya Sreenivasan MD FRCPC Ottawa ON Gaibrie Stephen MD, CCFP(EM) Toronto ON Kim Thompson MD London ON Anh Tran MD Vaughan ON Carolle Vienneau MD CCFP Komoka ON Todd Walters BA MD CCFP FCFP FAIME Toronto ON Karen Wang MEd MD FRCPC MSc Toronto ON Molly Wills M.A., MD Picton ON Michael Wills MD FRCPC (occupational medicine) Picton ON Margaret Wilson MD CCFP EM Ottawa ON Margaret Wolfe￾Wylie MD, FRCPC Toronto ON Brian Yau MD FRCPC Toronto ON Kim Zhou MD FRCPC Toronto ON Shady Abid MD. CFPC. Faculty Lecturer McGill university Montreal QC Vadeboncoeur Alain MD Longueuil QC Nabeel Ali MD, FRCPC (Pediatrics) Montreal QC Josiane D’Amico MD Professeur adjoint de clinique Montréal QC Yasmina Ammara MD Montreal QC Maria-Jesus Arrieta MD,CM, FRCPC, First Officer Infection Control CIUSSS Ouest de l'Île Montreal QC Madeleine Auclair MD, gastroenterologist Québec QC Pierre Auger Occupational medecine specialist Québec QC Gaétan Barrette MD, FRCP, Ex ministre de la Santé et des services sociaux Montréal QC Marie-Michelle Bellon Spécialiste en médecine interne Montréal QC Farah Benmohammed MD, MEng, CCFP Family medicine Montreal QC Karine Benoit Md, B.Sc Valleyfield QC Luc Bhérer M.D Occupational medicine specialist Quebec QC Valérie Bloch MD, DESS en Santé Publique, PhD en anthropologie Montreal QC Marie-Christine Blondin MD Varennes QC Vincent Bouchard￾Dechêne MD Montreal QC Amina Bougrine MD, FRCPC Montreal QC Nathalie Bourget MD Saint -Henri QC Cristian Budeci MD Montreal QC René Caissie Chirurgien Montreal QC Danielle Chahine MDCM, CFPC (Fellow) Montreal QC François de Champlain MD, FRCPC (EM) Verdun QC Julie Choquet MDCM Lachine QC Jessica Claveau MD Montreal QC Gabrielle Crépeau￾Gendron MD, FRCPC Montréal QC Ronald Dandurand MD, FRCPC, FACP, FCCP, Chief of Respiratory Medicine, Lakeshore General Hospital, Assistant Professor of Medicine, McGill University Montreal QC Andre Dascal MD FRCPC Montreal QC Petronela Dascalu MD,FRCPC Montreal QC Julian Doan MD Montreal QC Simon Drouin MD Montreal QC Morency Duchastel FMOQ Sherbrooke QC Melanie Duval MD Montreal QC Tamara Fitch MDCM, CCFP Montreal QC Isabelle-Anne Fontaine MD Québec QC Brenda Gentile MDCM, FRCPC Montreal QC Thibert Gilberte FRCPC Pointe-Caire QC Violayne Girardeau MD Montreal QC Mayuri Gupta MDCM CCFP Montreal QC Yasmin Halwani MDCM, FRCSC, FACS Montreal QC Jacynthe Harvey MD Montreal QC Konstantinos Hnaris MDCM, FRCPC Montreal QC Lisa Iannattone MD, FRCPC Montreal QC Sherif Karama MD PhD FRCPC Montreal QC Richard Knight MDCM Montreal QC Vladimir Kurgansky Urologist Hudson QC Zuzanna Labuda MD Montreal QC Nadine Lahoud MD Montréal QC Marie Laliberté MD Québec QC Alexandra Lao MD FRCPC Saint-Georges QC Marie-Claude Leblanc Md Repentigny QC Marie-Claude Letellier MD, M.Sc., Mcb.A. Québec QC Julie Marcheterre Md Sept-Îles QC Pierre Marsolais MD, FRPC, Interniste, Intensiviste, Professeur agrégé Université de Montréal Montraél QC Jérôme Mulhbacher MD, PhD Biochimie Québec QC Lavanya Narasiah MD. MSc. CCFP Montreal QC Andrew Bui-Nguyen MD Montréal QC Quoc Dinh Nguyen MD, MPH Montreal QC Hien Kiem Nguyen Thanh MD Laval QC Reuben Ostrofsky MD CM, CCFP (EM) Montreal QC Marie-Michèle Pagé MD Montréal QC Jean Papacot MD Montreal QC Louis Patry Médecin du travail Montreal QC Marie-Christine Perreault MD Montreal QC Magalie Pilon Md Becancour QC Caroline Pilon MD Montreal QC Marie-France Rioux Doctorat en médecine, médecine familiale Quebec QC Mélanie Roy FRCSC, ophtalmologiste Montreal QC Marie Roy MD Quebec QC Nader Sadeghi MD Montreal QC Mariame Makemin Sako Doctorat en médecine familiale Montreal QC Mireille Sayegh MD, Internal Medicine Beaconsfield QC Anita Siddiqui Doctor Montreal QC Aharon Silberman MDCM Montréal QC Valerie Stuckey MDCM FCFP Montréal QC Caroline Thibault Md Montreal QC Nataly Trang MD Montreal QC David Vas BSc, BFA, MD FCFPC(EM) Cote St Luc QC Yvonne Vasilie MD Beaconsfield QC Hugo Viens BSc Biologie, Md St-Lambert QC Pia Wintermark MD Montreal QC Christian Zalai MDCM, MSc, FRCSC, FACS, FABCRS Montreal QC Scientists Name Credentials and Affiliations City Province Malgorzata Gasperowicz PhD Biology, Endcoronavirus.org Canada-Outreach, Zero Covid Canada Calgary AB Jeremy Moreau PhD Calgary AB Conor A Ruzycki MSc Mechanical Engineering, PhD Candidate and Killam Scholar Edmonton AB HsingChi von Bergmann PhD Vancouver BC Krishanu Sankar Ph.D. Mathematics, Harvard University Vancouver BC Nazim Boudjada Ph.D. Physics Toronto ON Sue Gowans PhD Toronto ON Michael Ladouceur B.Sc, Prov, Officer, Assoc. UHMS, Air Scientist Kingston ON Fang Xi Lin MASt Applied Mathematics, PhD Candidate in Physics Toronto ON David Markin BSc Physics Ottawa ON Iacovos Michael PhD Toronto ON Natalie Morisset M.Sc. Ottawa ON Jennifer Murphy PhD Toronto ON Shraddha Pai Ph.D. Biological Sciences Toronto ON Kristen Pitzul Ph.D., Health Services Research, University of Toronto Toronto ON Jeremy Rothschild Ph.D. Candidate in Physics Toronto ON Meg Sears PhD Ottawa ON Jean-Paul R. Soucy PhD student in Epidemiology Toronto ON Aris Spourdalakis MsC Physics Toronto ON Francois Audet M.Sc. PhD Montreal QC Geneviève Baril￾Gingras Ph.D. sciences de l'administration, M.Sc. sciences biologiques (ergonomie) Québec QC François Béland PhD Laval QC Christine Boudreau B.Sc. Boucherville QC Normand Brais Ing., M.A.Sc., Ph.D. Rosemere QC Julie Champagne M. Sc. Biologie moléculaire Montréal QC Pierre Chevalier Ph.D., microbiologiste Québec QC André-Pierre Contandriopoulos PhD Sciences économique Montrèal QC Nancy Delagrave B.Sc. bidisciplinaire en mathématique-physique Montréal QC Alan C. Evans PhD, FRSC, FCAHS Montreal QC Simon Fissette M.Sc. Physics La Pocatiere QC Anne Gatignol DEPharm, PhD Montréal QC Mathieu Gauvin B. Eng., PhD Montreal QC Anne Renée Gravel Ph.D relations industrielles Montréal QC Marc Hamilton Microbiologist RMCCM Quebec QC Christian Lebeau Jacob Mcb.A Mascouche QC James King Professeur adjoint / PhD / Université de Montréal Montréal QC Isabelle Larrivée Doctorante en sociologie, cofondatrice de Des masques et de l’aération pour tout le monde Montréal QC René LeSage Professeur UQTR (retraité), PhD (chimie-phys) Shawinigan QC Leigh MacIntyre Bio-medical/Neuroscience Researcher Montreal QC Romaine Malenfant PhD sociologie Québec QC Geremia Massarelli Ph.D. Candidate in Physics Montréal QC Karen Messing Ph. D., O.C. (Officer) Montréal QC Nanouk Paré M.Sc, B.Sc Physique Montréal QC Michel Pronovost Microbiologist, M.Sc. Montréal QC Matthias Schoettle PhD in Computer Science Montréal QC Fatima Tokhmafshan Geneticist Montreal QC Christian Trahan Ph.D. molecular biology Montreal QC Occupational Health and Safety Scientists and Professionals Name Credentials and Affiliations City Province Nic Aulmann BNursing, MOccMed,H&S CRSP Nanaimo BC Courtney Gendron MPH Vancouver BC Masood Ahmed MS, CIH, CRSP Hamilton ON Xin Nuo Bai MPH Occupational and Environment Health Toronto ON Adeeta Bandoo BSc. Natural Sciences Brampton ON Phil Bigelow MHSc, PhD, ROH Waterloo ON James Brophy PhD, University of Windsor Windsor ON Marilyn Brownlee MScN, COHN(C), COHN-S/CM. CRSP Toronto ON Andrew Cutz DIH, CIH Markham ON Patricia Dufour Masters degree Quality Health and Safety Newmarket ON Rob Fernandes Certified Industrial Hygienist Georgetown ON Mariana Grinblat M.Sc., M. Eng. Toronto ON Todd Irick M.Sc., CIH Carleton Place ON Nancy Johnson OHS healthcare specialist (retired) Sudbury ON Margaret Keith PhD, University of Windsor Emeryville ON Matea Kokorovic MPH CIH Toronto ON Murray Lawrence BSc Hamilton ON Yang Luo M.Sc Occupational & Environmental Hygiene Toronto ON Ellen MacEachen PhD Waterloo ON Kenneth Major M.Sc.(A)., CIH, ROH Kingston ON Charles Pilger MSc, MEng, CIH(Ret'd) ROH (Ret'd) Toronto ON Robert Rae M.Eng. , CIH, ROH Mississauga ON Linda Raes CIH Sarnia ON Lydia Renton B.Sc., CIH, ROH, FAIHA Ottawa ON Luca Romano BSc. Vaughan ON Paul Sampara MEng ROH Fonthill ON Vinay Sharma National union Staff Toronto ON Umair Siddiqui BASc Occupational Health and Safety Pickering ON Rob Strang Engineer, ROH Orangeville ON Dorothy Wigmore MS Kitchener ON Nancy E. Wilk MHSc CIH Millgrove ON Stéphane Archambault MScA, ROH Repentigny QC Robert Bourbonnais MSc Hygiene Environment, DESS toxicologie, DSA Laval QC Natalie Fortin Chimiste, hygiéniste du travail ROH Jonquiere QC Pedro Grillo M.Sc.A. Montreal QC Carole Larose M.sc.a Montréal QC Sylvain Lequoc M.Sc.A. Montreal QC Ana Maria Seifert PhD en sante communautaire Montreal QC Robert Sinclair Bachelor of Applied Science. Occupational/Industrial Hygiene, Safety and Environment Dollard-des￾Ormeaux QC Andre Tartre M.Sc.A., CIH Montreal QC Sophie Therrien B.Sc. Montréal QC Valérie Turcotte M.Sc.(A), hygiéniste industrielle Montréal QC Loïc Wingert PhD Montréal QC Wayne Wood MScA, Occupational Health Montreal QC Lauren Bradshaw MSc Occupational Health, CRSP, CSP Regina SK Applied Science and Engineering Name Credentials and Affiliations City Province Robert Bean Ret. APEGA & ASET Calgary AB Scott Tavernini MSc. Mechanical Engineering Edmonton AB Adair Thompson Engineer, MBA Fort McMurray AB Brian Robertson PhD Physics; Prof. Emeritus, Mechanical & Materials Engineering West Vancouver BC George Skinner P.Eng., M.Sc. Mechanical Engineering New Westminster BC S. L. Wong Engineer Vancouver BC Mika Solway BSc civil/environmental engineering Fredericton NB Aaron Smith Engineer Halifax NS Karine St-Germain Mechanical engineering, PA LEED BD+C Halifax NS Erin Dixon MASc Toronto ON David Elfstrom P.Eng. Simcoe ON Barry Hunt BSc Kitchener ON Tom Kovendi Civil Engineering Oro-Medonte ON Michael Loughry Engineer Toronto ON Susan Fern Macdougall M.Sc Occupational Health, CRSP North York ON Paul Machuk Engineer Mississauga ON Hugh Montgomery BSc. Mechanical Engineering Toronto ON Ilvana Montgomery Electrical Engineer Toronto ON Vladimir Motovilov PhD, M.Sc. Senior Engineering Specialist Airbus St-Laurent ON Randy Park B.Sc. physics, M.Eng. Engineering Physics Toronto ON Susan Rowley Engineer Toronto ON Christine Shea MASc Mississauga ON Daniel Shea P.Eng Richmond Hill ON Cara Sloat B.A.Sc., Building Services Engineer (HVAC), mASHRAE Toronto ON Nicolas Smit BLs, Elastomeric Respirator Advocate Sudbury ON Aaron Soh H.BCs Physics and Statistics Kitchener ON Dominic Vita P.Eng. London ON Cheryl White P. Eng Toronto ON Andrew M. Wilson P.Eng.(ON,NT,NU), CEM Kitchener ON Julie Beausejour Engineer Montreal QC Denis Boudreau Bachelor of Electrical Engineering St-Lazare QC Sabrina Castelli M.Sc.A. hydrogéologie env., chimiste, Microbiologiste Agréée, biologiste Québec QC Michaël Côté Ing., P.Eng., Fellow d’Ingénieurs Canada Gatineau QC Manuelle Croft Ingénieure, LEED AP O+M, BCxP, RCx, ENV SP Montréal QC Sarah Dorner Ph.D., ing. Montréal QC Nicolas Drouin Bachelor of Engineering - Mechanical Baie-D'Urfe QC Carl Emanuel Ferrara P.Eng Montréal QC Natalia Motovilova Former Senior Engineering Specialist, Russian State Space Center, Design Bureau, Moscow Technical University. Master Diploma St-Laurent QC Henriot M Sabourin ingénieur Montréal QC Alain Trahan P.Eng. Terrebonne QC Karim Yaghmour M.A.Sc. Electrical Engineering Sherbrooke QC Nursing Professionals Name Credentials and Affiliations City Province Lesley Bell BScN, MBA Toronto ON Michelle Brosseau RN DipAd Ed LaSalle. ON Erna Bujna Occupational Health & Safety Specialist, Ontario Nurses’ Association (Retired) Kingsville ON Linda Haslam-Stroud RN Utterson ON Jean Kuehl Registered Nurse Kitchener ON Clea Lang M.Sc. NP Toronto ON Stacey Papernick Occupational Heath and Safety Specialist (previous position) Ontario Nurses’ Association Toronto ON Valerie Rzepka NP- PHC, BScN, MSc. DLSHTM Toronto ON Linda Silas President of the Canadian Federation of Nurses Unions Ottawa ON Barb Wahl Past President Ontario Nurses Association; BA Waterloo ON Keir White BScN Barrie ON Lesley Wylie RN, MHSM Toronto ON Isabelle Arsenault Nurse Lasalle QC Sarah Bachand Technicienne Montreal QC Denise Lavallee B Sc inf. M. Ed Ste-Béatrix QC Coline Saillard Infirmière Puéricultrice Montréal QC Melissa Tremblay Bac Lachine QC Supporting Signatures from International Physicians, Scientists, Occupational Health and Safety Professionals, Engineers and Nursing Professionals: International Physicians, Scientists, Occupational Health and Safety Professionals, Engineers and Nurses Name Credentials and Affiliations City Country Karen Cohn MS CIH Oakland CA - USA David F. Eldredge BSc Molecular/Microbiology Heber City UT - USA Maarten De Cock MSc Biology Antwerpen Belgium Trish Greenhalgh FMedSci (UK) Oxford UK Lucía Lara Engineer Horgen Switzerland Katrin Rabiei MD, PhD Gothenburg Sweden Jeffery K Smith IAQA, ISHRAE, CASANZ/Geographer/Consultant Geneva Switzerland Supporting Signatures from Other Canadian Professionals: Other Professionals Name Credentials and Affiliations City Province Dan Furst LL.B. Calgary AB Maria Infante PhD Resource Management and Environmental Studies Edmonton AB Kate Busby Architect AIBC AAA MArch BEDS Vancouver BC Tracy Casavant BASc (Chml Hons), MES Vancouver BC Cillian Collins Architect Vancouver BC Susan Z Martin BA in Health Information Science Victoria BC Ian Robertson Master of Architecture (M.Arch) Vancouver BC Michael Wisla CD, MAEd, ASP, CRM New Westminster BC Marie-Noëlle Ryan PhD Philosophy Moncton NB Julia M. Wright PhD, FRSC Halifax NS Hugh Armstrong PhD, Professor Emeritus, Carleton University Ottawa ON Joshua Atienza HBSc in Biochemistry and Molecular Biology Toronto ON M Becker B. Sc Dundas ON Michael Benoit Dip Brampton ON Colline Blanchard BScPharm Ottawa ON Glenn Butler WUCC, local 314 Oshawa ON Isabelle Carpenter Cadet Fort Albany ON Patty Coates President, Ontario Federation of Labour Toronto ON Bill Comeau M.Math Niagara ON Vance Coulas Vice President Unifor 3011 Rockland ON Leiya Dobson BSc Human Kinetics Ottawa ON Tracie Edward B.Sc. (Biology), B.Ed., Coordinator Health and Safety Services ETFO Toronto ON Agnieszka Filipek UFred COHSES program Thunder Bay ON Barry Fowlie Workers Comp/Health and Safety Guelph ON Julie Goldenson Ph.D. Toronto ON John Helson BA Oshawa ON Judy Howarth ONFCN Sault Ste. Marie ON Michael Hurley President Ontario Council of Hospital Unions-CUPE Toronto ON Ryan Imgrund BSc (Hons), BEd Georgina ON Michal Kapral Master of Health Informatics Toronto ON Steve Khan Honours Bachelor of Arts Toronto ON George T. Kitching BSc., MSc. Windsor ON Leesa Klich MSc Kitchener ON Dean Lasak Air Balancing Technologist Carlisle ON Peter Leventis MSc, PhD, PA (CCCPA) Toronto ON Carrie Loughry MBA Toronto ON Alan Majer MBA Toronto ON Jane McArthur M.A, PhD(ABD) Sociology Environmental and Occupational Health Tecumseh ON Michael McDonald FSA, FCIA Ottawa ON David McRobert B.Sc., MES, LL.B. Peterborough ON Jonathan Mesiano￾Crookston BScH, JD Toronto ON Sean O'Brien None Ottawa ON Katie Osborne BA, B.Ed (teacher) Oshawa ON Howard Pakosh BSEE Electrical Engineering Burlington ON Connor Power BA/COHS Toronto ON Inderdeep Sidhu MS Mississauga ON Brenda Snider SEIU Local 1 Canada Richmond Hill ON Andrew Thomson M.Arch, OAA, MRAIC Barrie ON Jaime Trick MScPT - Physical Therapist, BEd - Biology + Chemistry Ottawa ON Leah Ugulini Registered Dental Hygienist Fonthill ON Ryan Utter M.A. Ottawa ON Linda Vannucci Lawyer/Co-Director,Workers' Health And Safety Legal Clinic Toronto ON Katrina Wheaton BSc BEd Assistant Department Head Bargaining and Contract Services OECTA Toronto ON Andy Wong BASc Systems Design Markham ON John Wylie Ph.D physics university of Toronto Toronto ON Robert Belanger Bsc informatique Longueuil QC Magalie Bouchard PhD en sémiologie Montréal QC Jean-Francois Brodeur Paramedic, Health and Safety Representative Montreal QC Philippe Crevier Gestion stratégique SST - U Sherbrooke Montréal QC Élisabeth Cyr Maîtrise Québec QC France Delagrave M.Sc. en éducation, chargée de dossiers de santé publique Berthier-sur-Mer QC (retraitée) Gerald Denley BA Gatineau QC Patrick Déry Analyste en politiques publiques Laval QC Sophie Desz Sage-femme DE (France) Montreal QC Vincent Dinh MASc electronics engineering (in France) Montréal QC Alain Doiron BAC Génie Électrique Montréal QC Olivier Drouin M.Sc and founder of CovidEcolesQuebec Montreal QC Hélène Dumas Baccalauréat en microbiologie Notre-Dame-De￾L'Ile-Perrot QC Isabelle Gagné MASc chemical engineering Gatineau QC Johanne Heppell Bac. en philo, études de maîtrise en philo Plaisance QC Judith Huot Première vice-présidente FSSS-CSN Montréal QC Cindy Johnson Hygiéniste dentaire Lachine QC Russell Johnson CEGEP Diploma Carignan QC Begot Karine Salubrité Montreal QC Caroline KIlsdonk médecin vétérinaire et éthicienne/ m.v., M.A(bioéthique)) Brossard QC Élyse Laflamme BSc occupational therapist Montréal QC Linda Lapointe Inhalothérapeute Ville de Québec QC Catherine Leclerc PhD en sciences humaines/PhD in Humanities Montréal QC Daniel Lepine Inhalotherapeute Repentigny QC Mathieu Marion D. Phil. Oxon. Montréal QC Paul Mendes-Gagnier Préposé en entretien ménager Charlemagne QC Pascale Merlet MSc Administration de la santé Laval QC Alessandra Mezzetti PhD - Organic Chemistry Gatineau QC Elena Motovilova MM Saint-Laurent QC Christian Naud Fédération des professionnèles-CSN Québec QC Pierre Newberry B. Comp Sci and Engineering Westmount QC Charles Nguyen DEC Montreal QC Michel Paquette Ph.D. Philosophy (Decision theory) Montréal QC Maxime Richard Baccalauréat en biochimie de l'Université Laval 2008 Havre-Saint￾Pierre QC Mathieu Rousseau Bacc. psychologie Montreal QC Nathalie Roussy Hygiéniste dentaire Longueuil QC Danny Roy Fédération des professionnèles- CSN Québec QC Line Saad MBA Montreal QC Arlene Saint-Prix Bachelors and masters in Literature, Education and Translation Montréal QC Michel Seymour PhD. en philosophie Montreal QC Étienne St-Jean Ph.D. Administration, professeur titulaire, UQTR Trois-Rivières QC Debra Tacium B.A, DMV Sherbrooke QC Alexandre Triquet CEO, Tridan CBRNE Montreal QC Supporting Signatures from Other International Professionals: Other International Professionals Name Credentials and Affiliations City Country Theo Allen BSc Mathematics North Castle NY - USA Bronwyn Barry Architect San Francisco CA - USA Rabbi Kara Tav Rabbi, Chaplain New York City NY - USA Organizing bodies: Masks4Canada www.masks4canada.org Canadian Registration Board of Occupational Hygienists (CRBOH) https://www.crboh.ca/ Workplace Health Without Borders https://www.whwb.org/about-us/ Le collectif COVID-STOP http://www.covid-stop.ca/ Mission Panache Participating bodies: Occupational Hygiene Association of Ontario https://www.ohao.org Endcoronavirus.org https://www.endcoronavirus.org CovidisAirborne.org https://www.covidisairborne.org The Champlain Region Family Council Network (CRFCN) https://www.champlainfamilycouncils.ca Ontario North Family Councils Network (ONFCN) https://fco.ngo/connecting-councils/council/ontario-north-family-council-network Ontario Federation of Labour https://ofl.ca/ Service Employees International Union Local 1 Canada https://seiuhealthcare.ca/portfolio-item/seiu-local-1-canada-constitution/ Ontario Council of Hospital Unions-CUPE https://ochu.on.ca Canadian Federation of Nurses Unions https://nursesunions.ca REFERENCES 1. Morawska L, Milton D. It Is Time to Address Airborne Transmission of Coronavirus Disease 2019 (COVID-19) Clinical Infectious Diseases, Volume 71, Issue 9, 1 November 2020, Pages 2311– 2313, https://doi.org/10.1093/cid/ciaa939 2. Government of Canada. Coronavirus disease (COVID-19): Prevention and risks: How Covid-19 Spreads. https://www.canada.ca/en/public-health/services/diseases/2019-novel-coronavirus￾infection/prevention-risks.html#h (accessed Nov 15 2020) 3. Fang, F., Benson, C., del Rio, C., et al. COVID-19 – Lessons Learned and Questions Remaining. Clinical Infectious Diseases. 26 October 2020. https://academic.oup.com/cid/advance￾article/doi/10.1093/cid/ciaa1654/5940148 4. Nissen, K., Krambrich, J., Akaberi, D. et al. Long-distance airborne dispersal of SARS-CoV-2 in COVID-19 wards. Sci Rep 10, 19589 (2020). https://doi.org/10.1038/s41598-020-76442-2 5. Kutter J, de Meulder D, Bestebroer T, et al. SARS-CoV and SARS-CoV-2 are transmitted through the air between ferrets over more than one meter distance. BioRxiv. October 19 2020. https://doi.org/10.1101/2020.10.19.345363 6. Lednicky J et al. Viable SARS-CoV-2 in the air of a hospital room with COVID-19 patients. International Journal of Infectious Diseases. 11 September 2020. https://doi.org/10.1016/j.ijid.2020.09.025 7. Government of Canada. The Role of Bioaerosols and Indoor Ventilation in COVID-19 Transmission. September 28, 2020 http://science.gc.ca/eic/site/063.nsf/eng/h_98176.html (accessed Nov 15 2020) 8. Hedges K. Workplace Health Without Borders Letter. April 11 2020. https://www.whwb.org/wp￾content/uploads/2020/04/WHWB-letter-Minister-Hajdu-Dr-Theresa-Tam-11-Apr20.doc.pdf 9. Du CR, Wang SC, Yu MC et al. Effect of Ventilation Improvement during a Tuberculosis Outbreak in Underventilated University Buildings. Indoor Air 30(10). December 2019. 10. Occupational Safety and Health Administration. OSHA Alert: COVID-19 Guidance on Ventilation in the Workplace. Nov 2020. https://www.osha.gov/Publications/OSHA4103.pdf 11. Harvard TH Chan School of Public Health. Schools for Health: Risk Reduction Strategies for Reopening Schools. November 2020. https://schools.forhealth.org/risk-reduction-strategies-for￾reopening-schools/download/ (accessed Nov 17 2020) 12. CDC. COVID-19: Ventilation in Buildings. https://www.cdc.gov/coronavirus/2019- ncov/community/ventilation.html Dec 15 2020. (accessed Dec 17 2020) 13. ECDC. Heating, ventilation and air-conditioning systems in the context of COVID-19: first update. https://www.ecdc.europa.eu/en/publications-data/heating-ventilation-air-conditioning￾systems-covid-19 Nov 11 2020. (accessed Dec 17 2020) 14. ASHRAE. ASHRAE Position Document on Infectious Aerosols. April 14, 2020 https://www.ashrae.org/file%20library/about/position%20documents/pd_infectiousaerosols_2 020.pdf 15. WHO. The best time to prevent the next pandemic is now: countries join voices for better emergency preparedness. Oct 1 2020. https://www.who.int/news/item/01-10-2020-the-best￾time-to-prevent-the-next-pandemic-is-now-countries-join-voices-for-better-emergency￾preparedness (accessed Nov 16 2020) 16. (Oct 19 2020). Coronavirus: Germany improves ventilation to chase away Covid. BBC News. https://www.bbc.com/news/world-europe-54599593 17. Canadian Public Health Association. Sewage and sanitary reformers vs. Night filth and disease. https://www.cpha.ca/sewage-and-sanitary-reformers-vs-night-filth-and-disease (accessed Nov 15 2020)