A Call for the Universal Use of Respirators in Healthcare

Abstract

In summary: (a) surgical masks provide inadequate protection against airborne pathogens; (b) the current WHO guidelines are harming healthcare workers (HCWs) and patients; and (c) WHO as a global healthcare safety leader has the power to reduce disease burden in healthcare settings through more effective advocacy. WHO should lead decisively toward safer healthcare by establishing respirators as the universal default for all healthcare encounters, with clearly defined, locally-determined off-ramps based on transparent risk indicators and the use of effective engineering controls. This recommendation would align WHO policy with science and existing safety standards and would improve safety for both patients and healthcare providers.

Keywords

respirators healthcare WHO

Editor's Note

Since 2020, NEW SOLUTIONS has been publishing about protection against SARS-CoV-2 specifically and aerosol-transmitted infectious disease generally. Our COVID-19 Collection^a has more than 45 publications, and our Barrier Face Coverings Collection^b has an exchange between Brosseau and Nicas on that subject. In keeping with the Journal's long-standing interest in these issues, we took an immediate interest in publishing this letter when we became aware of its existence.

Cover Note From the Authors of the Letter to the World Health Organization on Respirators and Surgical Masks

This letter, originally sent to the World Health Organization on January 6, 2026, highlights the disconnection between the well-established scientific understanding of airborne transmission of infectious agents such as SARS CoV-2 and the current WHO and other guidance on respiratory protection in healthcare settings.

The issues raised in the letter received substantial public attention, including coverage in The Guardian^c and Forbes.^d This coverage reflects the recognition that scientific advances have made quite clear that the substantial superiority of respirators over surgical masks for protection against airborne infectious agents has direct implications for worker and patient protection.

We note that we did not receive a response from the WHO to our January 6 letter. On February 18, 2026, we sent a follow-up communication requesting a meeting to discuss these issues and their broader implications for global health guidance. As of this writing, we have not received a reply.

Our intent has been constructive: to support alignment of global guidance with scientific understanding and to contribute to effective protection of healthcare workers and patients.

Recognizing that New Solutions is oriented toward the unfinished business of protecting workers (in their occupations and in the communities in which they live), we want to make two brief observations about how our advocacy for respirators in health care relates to other contexts that have important differences from this one.

First, we emphasize that respecting the hierarchy of controls,^e as we do, does not diminish our zeal for improving personal protective equipment (PPE) in healthcare. In industrial settings, respirators are often rightly seen as band-aids that employers favor so as to avoid expensive engineering controls and that shift responsibility to the workers. But here, respirators are an essential element in a layered approach to reducing viral exposure, which neither engineering controls nor PPE can adequately do on their own. More importantly, an infectious disease is simply vastly different from a chemical toxicant; a coke oven worker who doffs her respirator is only hurting herself, whereas a symptomatic (or presymptomatic) health care worker who refuses to wear one may be infecting both colleagues and patients.

Second, some of the informal pushback we’ve received from medical doctors proves this previous point. Given the long-standing and intense opposition to OSHA's attempts to reduce workplace transmission of infectious disease (one of us was OSHA's director of health standards when groups like the Association for Professionals in Infection Control and Epidemiology (APIC) and the Society for Healthcare Epidemiology of America (SHEA) helped scuttle the 1998 tuberculosis standard), it is no surprise that MDs resist others suggesting they could/should do better. We expected to hear the claims that respirators are uncomfortable, promote acne, or can even cause “CO₂ poisoning,” along with concern that patients value seeing the facial expressions of their providers, and we were not disappointed. But several MDs have missed the point entirely, and only react to the half of the message that urges them to better protect themselves. We’ve heard that respirator-wearing should not be the default position because MDs “know in what situations we need to protect ourselves from infectious patients.” This may be true, but where is the concern that physicians should “first do no harm” to those who come to them for treatment and who prefer not to return home with a new and different malady? After all, there are no situations where an MD simply must unmask, whereas patients are unable to use a respirator when access to their mouth or nose is needed for medical reasons.

There is also a deeper historical pattern worth noting. Resistance to recognizing transmission risks from caregivers themselves is not new. The rejection of Ignaz Semmelweis's handwashing recommendations in the nineteenth century was grounded in part in the belief that physicians, as gentlemen, could not be sources of harm. Today, we know that clinicians—like others—can be asymptomatic or presymptomatic carriers of infectious disease, and yet working while sick remains common in healthcare settings.

At the same time, the claim that physicians “know” when protection is needed rests on a framework that is itself flawed. What has long been taught as the guiding conditions for transmission—particularly the focus on so-called “aerosol-generating procedures”—does not reflect current scientific understanding. The framework that has long guided such judgments—the droplet-based model of transmission—has been scientifically superseded. It specifies risk conditions incorrectly, leading to systematic underestimation of when protection is needed. Correcting the widespread harmful application of this misunderstanding in policy and practice is a central purpose of our letter, due to its implications for transmission and necessary precautions, as was the case for handwashing in Semmelweis's time and for recognition of bloodborne transmission during the early years of AIDS.

Yaneer Bar-Yam

Adam Finkel

Greta Fox

Lotta-Maria Oksanen

Špela Šalamon

Liza K. Tóth

Joe Vipond

Dear Director-General Ghebreyesus and Colleagues,

Thank you for your efforts to advance global public health through turbulent times. We are experts from around the globe in medicine, public health, law, industrial hygiene, and other disciplines, and we write today out of deep concern — and with sincere hope for change — regarding the World Health Organization's historical and ongoing position on failing to advocate for the use of respirators^f in healthcare settings.

In summary: (1) Surgical masks provide inadequate protection against airborne pathogens; (2) the current WHO guidelines are harming healthcare workers (HCWs) and patients; and (3) WHO as a global healthcare safety leader has the power to reduce disease burden in healthcare settings through more effective advocacy.

WHO should lead decisively toward safer healthcare by establishing respirators as the universal default for all healthcare encounters, with clearly defined, locally-determined off-ramps based on transparent risk indicators and the use of effective engineering controls. This recommendation would align WHO policy with science and existing safety standards and would improve safety for both patients and healthcare providers.

We present our rationale in more detail below, and we offer a seven-step plan WHO should implement. The plan includes improving IPC (Infection Prevention and Control) Guidelines, correcting prior misinformation, supporting equitable access to respirators worldwide, and convening a broadly representative panel of experts and stakeholders to promote implementation of these improved healthcare safety measures.

The Time is Now

In light of WHO's recent recognition of the airborne transmission of SARS-CoV-2 and other pathogens,¹ and in light of a consistent pipeline of scientifically-accepted evidence of the superiority of respirators over surgical masks, we respectfully submit that the time is now for WHO to correct prior missteps and properly protect patients and healthcare workers (HCWs) by advocating for respirator use as a universal standard in healthcare. We note that such a recommendation has recently been proposed in Canada² and affirmed in the UK.³

We urge WHO to recommend respirators being used in every encounter in all healthcare settings, as a reasonable default position to protect HCWs and patients against respiratory transmitted pathogens such as SARS-CoV-2 which continues to circulate globally and to mutate. WHO could certainly also recommend that governments and establishments establish off-ramps when respirators need not be used, based on local and transparent risk assessment of factors such as community infection rates, CO₂ (or viral) levels in room air, and the use of far UV light, HEPA filtration, or other environmental controls, etc. We emphasize that the evidence shows that on the ground, mandates and norms are more effective than mere recommendations.⁴

The remainder of this letter discusses the urgent need for more respiratory protection in healthcare, and the use of effective devices rather than ineffective ones. Although respiratory protection is merely one element in a comprehensive response to reduce illness in HCWs and patients, we confine our remarks to this element for reasons that will be obvious in the document.

The Case is Clear: Surgical Masks Do Not Provide Adequate Protection

There is now overwhelming evidence—from decades of laboratory science, aerosol physics, and occupational hygiene—that surgical masks, which were not designed for wearer or patient protection against respiratory infection, are vastly inferior to respirators.⁵ The CDC states: “Surgical masks are not respirators. They are disposable coverings designed to be loose-fitting over the user's nose and mouth.”⁶ Respirators are regulated on their ability to achieve a specific minimum protection factor, while surgical masks are not.⁷ Respirators for health care settings are plentiful, affordable, comfortable, and safe, with new models developed routinely that provide additional breathability, ecological sustainability, and reusability. There is no rational justification remaining for prioritizing or using surgical masks in healthcare environments. There is even less justification for allowing HCWs to wear no face covering at all, or for facilities to discourage respirator or mask use by patients.

The use of surgical masks as primary respiratory protection in healthcare settings represents a critical mismatch between the hazard and the protective equipment provided and is fundamentally inconsistent with core principles of occupational safety.⁸ It is now well-established that humans infected with pathogens continuously emit potentially infectious, aerosol-sized particles during all respiratory activities.²^,⁹ When we combine this with what we know about exposure volumes, the contrast becomes stark: a few ballistic droplets have a very narrow target zone, whereas aerosols spread throughout the entire breathing airspace.^10,11 Moreover, infections initiated in the lower respiratory tract typically require lower infectious doses and lead to more severe clinical presentations.¹² So currently, we are protecting HCWs and their patients against a droplet in an ocean of aerosols. This inadequacy would not be tolerated in any other industry—nor should it be in healthcare.

We see the consequences of this failed protection every day: healthcare-acquired infections¹³ (and subsequent deaths and chronic illness) are alarmingly common, and HCWs consistently top the statistics for acute and chronic infection-related absences.¹⁴ It is eye-opening that SARS-CoV-2 infection caused a 250% increase in HCW's work-related fatal accidents (death due to occupational SARS-CoV-2) in 2020 in EU data. In addition, presenteeism (working while ill) is pervasive in health care settings.¹⁵ These tendencies place immense strain on our already critically burdened system.

We have an undeniable opportunity to radically improve this situation. Laboratory and field studies have long shown that respirators can reduce inhaled exposure to infectious aerosols by approximately 80% and up to 98%, even without professional fit testing.^16–18 Initial and periodic fit testing further improves respirator performance, may be required by regulation in some settings, and is not unduly burdensome to employers. When both parties in a healthcare encounter wear respirators, the resulting exposure can be reduced by 96% or more¹⁹ (Bagheri et al. 2021). In stark contrast, surgical masks tend to reduce exposure merely by about 40% or even less.²⁰ This is far from a marginal difference; depending on the shape and parameters of the dose-response function relating the concentration of SARS-CoV-2 or other virions in the breathing zone to the infectious dose for any particular individual, a respirator could easily prevent transmission of disease between an HCW and patient, whereas a surgical mask could easily fail to reduce exposure to below the infectious dose.

Randomized controlled trials and epidemiological studies that attempt to assess the impact of surgical masks or respirators in reducing disease, hospitalizations, or deaths in community settings are inherently flawed and misleading due to substantial methodological limitations and lack of statistical power.^5,21 They are not capable of measuring true exposure reduction, because subjects in the “protected” group may be unmasked for large portions of the day, while subjects in the control group may be protected at some times.²² Studies that measure disease or severe disease add substantial and unmeasured noise from individual variations in susceptibility and exposure.²³ At best, these studies show that mandates for respirator use may be difficult to enforce outside the workplace— they do not and cannot disprove the well-documented physical efficacy of respirators themselves.²⁴

Current WHO Guidance is Contributing to Harm

While we acknowledge the important work that WHO did in clarifying the airborne nature of SARS-CoV-2 and other pathogens,²⁵ we are deeply alarmed that WHO continues to support policies allowing HCWs to wear surgical masks — or no respiratory protection at all — when caring for patients. This position is not only scientifically indefensible but also dangerous:

It contributes directly to HCW acute and chronic illness, burnout, and staffing shortages.

It exposes patients to preventable and potentially even lethal risk. Hospital-associated infections by SARS-CoV-2 carry consistently higher mortality rates than community-associated infections.²⁶ Patients who want to protect themselves are needlessly and wrongfully placed in a vulnerable position when HCWs refuse to use respirators and may even discourage or forbid patients from doing so.

For patients, the time spent in healthcare settings may represent the single highest exposure risk they face all year—due to high infection prevalence, close proximity, and lack of airborne precautions.

It erodes public trust and exposes a lack of competence, professionalism and ethics in healthcare in a very visible way, thus damaging the reputation and influence of the medical profession which can lead to reduced compliance with professional guidance and increased vulnerability to misinformation.²⁷

The Path Forward: WHO as a Global Healthcare Safety Leader

While we understand that WHO does not directly mandate policies worldwide, its influence on global health policy is profound. We urge you to act now to address the threat of airborne transmission, and take the following steps:

Update IPC Guidelines to recommend respirators (e.g., N95, FFP2/3, elastomeric) in all healthcare settings—not just during outbreaks or high-risk procedures, but as a baseline occupational safety standard. The Guidelines could recommend locally-determined off-ramps based on precautionary interpretations of current local and establishment-specific conditions.

Revisit prior statements about how SARS-CoV-2 is transmitted, and unambiguously inform the public that it spreads via airborne respiratory particles (a term subsuming both “aerosols” as well as “droplets”). Restoring public trust begins with transparency and accountability. To close the knowledge gap, provide comprehensive training and education.

Leverage WHO's partnerships and procurement infrastructure to support equitable access to certified respirators globally—particularly for healthcare systems in low- and middle-income countries. Over time, surgical masks should be produced in progressively smaller quantities, as safer, more effective respirators have been and remain readily available.

Launch global campaigns normalizing the use of respirators as a basic tool of infection prevention—not as emergency gear, but as modern personal protective equipment.

Integrate universal respiratory protection into pandemic preparedness frameworks, including the forthcoming WHO Pandemic Accord. Respirators must no longer be treated as optional, nor as luxury items.

Convene multidisciplinary experts, including industrial hygienists, aerosol scientists, social scientists, healthcare workers, disease transmission modelers, and patient advocates, as well as infectious disease modelers, to advise on implementation and adherence.

Clearly, publicly, and regularly reinforce the message that while WHO had stopped referring to SARS-CoV-2 as a Public Health Emergency of International Concern in 2023, the pandemic is still ongoing. This will make countries accountable for mitigating the ongoing risks or covering the ongoing costs of inaction.

We emphasize that if it is the case that not every country can afford to shift from surgical masks to respirators (which we dispute, given how small this marginal cost is compared to the much larger costs of health care), WHO should not recommend waiting until these recommendations can be applied everywhere before they are applied anywhere. We must not compromise everyone's health by citing the impossibility of a uniform, instantaneous change. Instead, we must strive for continuous improvement, where best practices and innovations gradually spread from early adopters to others, progressively elevating the overall level of protection across the entire system.^g

These steps would not only align WHO policy with current science—they would save lives, particularly of the HCWs and patients most vulnerable to healthcare-acquired infections. They would also signal that WHO has the courage and humility to adapt, lead and usher in a new era of respiratory protection.

A Final Thought

We understand that many public health leaders made decisions under conditions of crisis and uncertainty. But now that it is universally acknowledged that SARS-CoV-2 and other respiratory-transmitted viruses are airborne, inaction is no longer justifiable. History will remember not only what WHO said during the early pandemic—but how it responded after the evidence for airborne transmission became indisputable, and in light of the long-settled scientific conclusion that only respirators can provide significant exposure and risk reduction.

We urge you to lead decisively—with scientific rigor, equity, and integrity. We are confident that WHO can chart a bold course—one that future generations will look back on as a pivotal step toward a healthier, fairer, and more resilient global health system.

We would be happy to discuss the content of this letter with you and any others at WHO; please contact us via Dr. Adam Finkel (adfinkel@umich.edu).

Authors, Endorsers, and Signatories

This letter was authored by a core drafting group drawn from medicine, public health, occupational health, law, and systems science, working collaboratively across disciplines. It is endorsed by senior clinicians, public health leaders, occupational hygienists, aerosol scientists, legal scholars, patient advocates, and policy experts from multiple countries. The letter is supported by over 2,300 signatories worldwide, representing healthcare workers, researchers, educators, patients, and concerned members of the global health community. A complete list of endorsers and signatories is provided in Appendix A. Affiliations are listed for identification purposes only.

Sincerely,

Yaneer Bar-Yam, PhD, co-Founder, World Health Network; Professor and President, New England Complex Systems Institute

Adam M. Finkel, ScD, CIH, Clinical Professor (Adjunct) of Environmental Health Sciences, University of Michigan School of Public Health, and formerly (1995-2000) the chief regulatory official at the U.S. Occupational Safety and Health Administration

Greta Fox, MS, NP, World Health Network (WHN)

Lotta-Maria Oksanen, MD, PhD, Postdoctoral Researcher, Airborne Infections and Protective Measures; Resident Physician, University of Helsinki; Faculty of Medicine, Helsinki, Finland

Špela Šalamon, MD, PhD, (World Health Network)

Liza K. Tóth, JD, BSc (Chem), Retired US Intellectual Property Attorney (CA, USPTO), Science and Policy Member, World Health Network

Joe Vipond, MD, FCFP, CCFP (EM), BSc (hon), Clinical Assistant Professor Department of Emergency Medicine, University of Calgary, Co-Chair and Co-founder of the Canadian Covid Society

Endorsed By:

Verónica Athié-Morales, BSc, MSc, PhD—Microbiology, Biochemistry, Toxicology, Immunology, ConCiencia ECAI, Mexico

Samuel R. Bagenstos, JD, Frank G. Millard Professor of Law at the University of Michigan

Michael Baker, MBChB, FAFPHM, FNZCPHM, Professor of Public Health, University of Otago, Wellington, New Zealand

Jeffrey S Birkner PhD, CIH

Ludovica Bricca, MD, Specializing in Hygiene and Preventative Medicine, Università della Cattolica del Sacro Cuore—Rome

Lisa M Brosseau, ScD, CIH, Professor (retired), Owner, Colfax South LLC; Research Consultant, University of Minnesota, Center for Infectious Disease Research and Policy

Professor Giorgio Buonanno, PhD, University of Cassino and Southern Lazio, Italy. Adjunct professor, Queensland University of Technology (QUT), Brisbane, Australia

Danilo Buonsenso, MD, MSc, PhD, Università Cattolica del Sacro Cuore, Roma, Italia

Professor Stephanie J. Dancer, BSc, MB.BS, MD, MSc, FRCPath, DTM&H, FRCP(Ed), FESCMID, FISAC, Consultant Microbiologist, NHS Lanarkshire & Professor of Microbiology, Edinburgh Napier University, Scotland

Joseph L. Eastman, PhD, WHN Science and Policy Group

Andrew Ewing, PhD, Chair, WHN Long COVID Advisory Group; Professor of Chemistry and Molecular Biology, University of Gothenburg, Sweden; Elected member of the Swedish Academy of Sciences

Anthony Fenn, FRCS, MBA, MSc, Public Health

Eric Feigl-Ding, ScD, Epidemiologist, Health Economist

Lyne Filiatrault, MDCM, FRCPC, Canadian Aerosol Transmission Coalition

Gregg Gonsalves, PhD, Associate Professor, Epidemiology of Microbial Diseases, Yale School of Public Health

Trisha Greenhalgh, OBE, MD, FRCP, FRCGP, FFPH, Professor of Primary Care Health Sciences, University of Oxford

Tee L. Guidotti, MD, MPH, DABT, FRCPC, FFOM RCP, FFPM RCPI, Fellow, Royal Society of Canada, Retired Professor of Occupational and Environmental Medicine, Pulmonary Medicine, Epidemiology; University of Alberta, The George Washington University

Dr Rajiv Kumar Gupta, MD, Professor and Head, Community Medicine, Govt. Medical College Jammu, India

Matti TJ Heino, Social Psychologist

Kevin Hedges, PhD, FAIOH, CIH, COH, Workplace Health Without Borders WHWB (International) and Canadian Aerosol Transmission Coalition (CATC)

Michael Hoerger, PhD, MSCR, MBA, Program Lead for Cancer Population Science, Tulane Cancer Center

Jonathan Howard, MD, Chief of Neurology, Bellevue Hospital

Barry Hunt, BSc, Executive Director, Coalition for Community and Healthcare Acquired Infection Reduction (CHAIR)

Jose L. Jimenez, PhD, Distinguished Professor of Chemistry; Fellow of CIRES, University of Colorado

Dr David Joffe MBBS(Hon.) PhD, FRACP, World Health Network Long Covid Expert Advisory Group, Vice-Chair, Visiting Medical Officer, Respiratory and Sleep Medicine, Royal North Shore Hospital

Douglas B. Kell CBE, Research Chair in Systems Biology, University of Liverpool

Dr. Asad Khan, FRCP(Edin), FRACP, Consultant Respiratory Physician, Manchester, UK (Retired)

Prashant Kumar, PhD, Global Centre for Clean Air Research (GCARE), University of Surrey, UK

Professor Julia Lawton, School of Population Health Sciences, University of Edinburgh

Cam Mackey, President & CEO, International Safety Equipment Association (ISEA)

Dr. Nancy Malek, MBBS, FANZCA, WHN Long COVID Advisory Group

Nancy M. McClellan, MPH, CIH, CHMM, CEO, Occupational Health Management, PLLC

Professor Martin McKee, CBE, MD, DSc, FMedSci, Professor of European Public Health, London School of Hygiene and Tropical Medicine, Past President, British Medical Association & European Public Health Association, Research Director European Observatory on Health Systems & Policies

George Monbiot, author, journalist, environmental activist

Distinguished Professor Lidia Morawska, PhD, Director, International Laboratory for Air Quality and Health (WHO CC for Air Quality and Health), Queensland University of Technology, Brisbane, Australia

Stefano Pallanti, MD, PhD, Instituto di Nueroscienze

Narender Paul, Chief Operating Officer CORD, India

Prof Etheresia Pretorius, PhD, Stellenbosch University South Africa

Prof. Sunil Raina, MD, Dr. RP Government Medical College, Tanda (HP), India & World Health Network

Walter Ricciardi, MD, MPH, MSc, Hon PhD, Professor of Hygiene and Director of the school of Hygiene and Public Health, Università Cattolica del Sacro Cuore (UCSC) (Rome). He is Chair of the Mission Board for Cancer (EC), the Scientific Committee of Human Technopole Foundation, and the European Mission Board for Vaccination.

James D. Sessford, R. Kin, PhD, Research Associate at University of Toronto, Co-Investigator on long COVID grant from Long COVID Web

Kristin Shrader-Frechette, PhD, O’Neill Family Professor Emerita, Department of Philosophy and Department of Biological Sciences, University of Notre Dame

Lawrence Sloan, MBA, CAE, FASAE, CEO, American Industrial Hygiene Association (AIHA)

Raymond Tellier MD MSc FRCPC CSPQ FCCM D(ABMM), Associate Professor McGill University

Desmond Whyms, BA, MA, DipPH, Retired Senior Public Health Advisor UK DFID/FCDO

Footnotes

Declaration of Conflicting Interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

ORCID iD

Adam M. Finkel

Notes

Author Biographies

Dr. Yaneer Bar-Yam is a physicist and complexity scientist and the founding president of the New England Complex Systems Institute. His work focuses on complex systems, global risk, and crisis response across public health, economics, and security. During the COVID-19 pandemic, he was among the earliest to warn of its global spread and to advocate for prevention-focused strategies. He is a co-founder of the World Health Network and works on science-based approaches to infection prevention, clean air, and respiratory protection.

Dr. Adam M. Finkel is a clinical professor of environmental health sciences at the University of Michigan School of Public Health. He has previously been a professor at Princeton University (School of Public and International Affairs), the University of Pennsylvania (Law School), and Rutgers University (School of Medicine). From 1995 to 2005, he was a senior executive at the U.S. Occupational Safety and Health Administration, first as OSHA's director of health standards and later as its regional administrator in the Rocky Mountain states. He led the development of OSHA's Respiratory Protection Standard (29 CFR 1910.134) in the late 1990s.

Greta Fox, FNP-BC, holds a B.S.N. in Nursing from Boston College and an M.S.N. in Family and Community Health from the University of Massachusetts/Lowell. She has worked at the Boston Evening Clinic, New England Baptist Hospital, Urban Woman and Child Health, Uphams Corner Health Center, and Concord OB/Gyn Associates. She has mentored students, lectured at Salem State College, and advocated for reproductive rights. A founding member of WHN, her focus includes HAI prevention and COVID event safety, emphasizing PPE and indoor air quality. She manages David Fox Photography, advocating for COVID-19 awareness and safety in the meetings and events industry.

Dr. Lotta-Maria Oksanen is a physician and Doctor of Medicine (MD, PhD), trained at the University of Helsinki. Her doctoral research focused on understanding airborne transmission and protection against it, and her work spans multidisciplinary research on infection prevention, respiratory protection, aerosol generation, and pandemic preparedness. She is based at the University of Helsinki and Helsinki University Hospital, where she currently works on occupational health research questions, infection control, and the health impacts of infections.

Dr. Špela Šalamon is a biomedical scientist and board-certified specialist physician in nuclear medicine at the forefront of redefining the long-term risks of COVID-19. Her award-winning work on the vascular pathogenesis of SARS-CoV-2, widely discussed analysis of its immune-dysregulating effects, and synthesis of systemic pathophysiology are shifting the paradigm for understanding Long COVID. Dr. Šalamon is a Scientific Advisor for the World Health Network (WHN), Editor of its peer-reviewed indexed journal WHN Science Communications, and is involved in initiatives like the global expert consensus and open letter to the WHO advocating for respirator masks in healthcare. She actively bridges research and patient advocacy through engagement with the sufferers’ community and is a leading member of the International Society for Long Covid and PAIS.

Liza Toth is a retired intellectual property attorney and public interest advocate, with decades of experience in patent law, litigation, corporate strategy, and interdisciplinary problem solving. Licensed in California and before the U.S. Patent and Trademark Office, she served as Vice President of IP for both private and publicly traded multinational technology firms, managing portfolios across sectors including pharmaceuticals, signal processing, medical devices, telecom, and GPS. Since retiring, she has turned her attention to public advocacy and systems transformation, co-founding the environmental NGO Saving Our Planet and contributing actively to the World Health Network (WHN) as a Member of its Science Policy Group.

Dr. Joe Vipond has been an emergency physician for 25 years, currently practicing at the Rockyview General Hospital in Calgary, AB. He is also a clinical assistant professor at the University of Calgary. His environmental advocacy includes being a former president of the Canadian Association of Physicians for the Environment, the co-founder and co-chair of the Calgary Climate Hub, and a board member of the Global Climate and Health Alliance. During COVID, he was a strong proponent for public health protections, and co-founded the organizations Masks4Canada, Protect Our Province Alberta, and the Canadian Covid Society. He is currently an advisor to the World Health Network in its infection prevention team.

References

Morawska

Bahnfleth

Bluyssen

, et al.

Coronavirus disease 2019 and airborne transmission: science rejected, lives lost. Can society do better?

Clin Infect Dis 2023; 76: 1854–1859.

Canadian Standards Association (CSA). Public draft of CSA Z94.4-25: Selection, Use, and Care of Respirators. (2025).

British Occupational Hygiene Society. Guidance for Healthcare Employers and Workers on the use of Fluid Resistant Surgical Masks and Respirators. https://www.bohs.org/app/uploads/2025/07/COSHH-and-Healthcare-Respiratory-Protection.pdf. (2025, Accessed 28 April 2026).

Jin

English

. Collectivism predicts mask use during COVID-19. Proc Natl Acad Sci USA 2021; 118: e2021793118.

Greenhalgh

MacIntyre

Baker

, et al. Masks and respirators for prevention of respiratory infections: a state of the science review. Clin Microbiol Rev 2024; 37: e00124–23.

CDC/NIOSH 2017. Understanding respiratory protection options in healthcare: the overlooked elastomeric. https://www.cdc.gov/niosh/bulletin/2017/healthcare-elastomerics.html (2017, Accessed 29 April 2026).

CCOHS. Respirators—respirators versus surgical masks versus non-medical masks. Canadian Center for Occupational Health and Safety. https://www.ccohs.ca/oshanswers/prevention/ppe/surgical_mask.html. (2025, Accessed 28 April 2026).

IOSH. The road to safe and healthy work. https://iosh.com/about/what-we-do/osh-principles. (2025, Accessed 28 April 2026).

Bagheri

Schlenczek

Turco

, et al. Size, concentration, and origin of human exhaled particles and their dependence on human factors with implications on infection transmission. J Aerosol Sci 2023; 168. DOI: https://doi.org/10.1016/j.jaerosci.2022.106102.

10.

US EPA. Indoor Air and Coronavirus (COVID-19). https://www.epa.gov/indoor-air-quality-iaq/indoor-air-and-coronavirus-covid-19 (2025, Accessed 28 April 2026).

11.

Wang

Prather

Sznitman

, et al. Airborne transmission of respiratory viruses. Science 2021; 373: eabd9149.

12.

Thomas

. Particle size and pathogenicity in the respiratory tract. Virulence 2013; 4: 847–858.

13.

Sandu

Chifiriuc

Vrancianu

, et al. Healthcare-associated infections: the role of microbial and environmental factors in infection control—a narrative review. Infect Dis Ther 2025; 14: 933–971.

14.

Vroonhof

, et al. OSH in figures in the health and social care sector. EU OSHA. (2024, Accessed 28 April 2026).

15.

Linsenmeyer

Mohr

Gupta

, et al. Sickness presenteeism in healthcare workers during the coronavirus disease 2019 (COVID-19) pandemic: an observational cohort study. Infect Control Hosp Epidemiol 2023; 44: 1693–1696.

16.

Lai

Coleman

Tai

SHS

, et al. Relative efficacy of masks and respirators as source control for viral aerosol shedding from people infected with SARS-CoV-2: a controlled human exhaled breath aerosol experimental study. eBioMedicine 2024; 104.

17.

Duncan

Bodurtha

Naqvi

. The protective performance of reusable cloth face masks, disposable procedure masks, KN95 masks and N95 respirators: filtration and total inward leakage. PLOS ONE 2021; 16: e0258191.

18.

Clapp

Sickbert-Bennett

Samet

, et al. Evaluation of cloth masks and modified procedure masks as personal protective equipment for the public during the COVID-19 pandemic. JAMA Intern Med 2021; 181: 463–469.

19.

Bagheri

Thiede

Hejazi

, et al. An upper bound on one-to-one exposure to infectious human respiratory particles. Proc Natl Acad Sci U S A 2021; 118(49, (Accessed 28 April 2026). DOI: 10.1073/pnas.2110117118.

20.

US EPA. EPA researchers test effectiveness of face masks, disinfection methods against COVID-19. https://www.epa.gov/sciencematters/epa-researchers-test-effectiveness-face-masks-disinfection-methods-against-covid-19 (2021, Accessed 28 April 2026).

21.

Kollepara

Siegenfeld

Taleb

, et al. Unmasking the mask studies: why the effectiveness of surgical masks in preventing respiratory infections has been underestimated. J Travel Med 2021; 28. DOI: 10.1093/jtm/taab144.

22.

Alfelali

Haworth

Barasheed

, et al. Facemask against viral respiratory infections among Hajj pilgrims: a challenging cluster-randomized trial. PLoS One 2020; 15: e0240287.

23.

Finkel

. More serious flaws are overlooked in the dispute over respirators versus surgical masks. British Med J (rapid response. https://www.bmj.com/content/393/bmj.s725/rr-1 .

24.

Brosseau

MacIntyre

Ulrich

, et al. COMMENTARY: Wear a respirator, not a cloth or surgical mask, to protect against respiratory viruses. https://www.cidrap.umn.edu/covid-19/commentary-wear-respirator-not-cloth-or-surgical-mask-protect-against-respiratory-viruses. (2023, Accessed 28 April 2026).

25.

WHO. Global technical consultation report on proposed terminology for pathogens that transmit through the air. https://www.who.int/publications/m/item/global-technical-consultation-report-on-proposed-terminology-for-pathogens-that-transmit-through-the-air. (2025, Accessed 28 April 2026).

26.

Langlete

Eriksen-Volle

Paulsen

, et al. Healthcare-associated COVID-19 infections and mortality. J Hosp Infect 2025; 158: 61–68.

27.

Dorfman

Raz

Berger

. Physicians’ refusal to wear masks to protect vulnerable patients—an ethical dilemma for the medical profession. JAMA Health Forum 2023; 4: e233780–e.

28.

Spang

Pieper

. The tiny effects of respiratory masks on physiological, subjective, and behavioral measures under mental load in a randomized controlled trial. Sci Rep 2021; 11: 19601.