Is There Really Strong Evidence for Wearing Masks?
During the COVID-19 pandemic, there has been conflicting advice about wearing face masks or face coverings, even within the same public health agencies. For example, some medical organizations claim that wearing a mask only protects others from you if you are carrying the virus, but urge you to wear one if you are in close contact with a COVID-19 patient — which infers that a mask could protect you from an infected person.
The advice raises several questions. First, many people can be carrying the virus and not know it because they are asymptomatic and have not been tested. How would these people know to wear a mask? Secondly, if a mask is indicated if you are in close contact with a COVID-19 patient, then that would indicate that a mask does protect you from others and not just others from you. So, which is the truth?
There is another element to the conflicting advice. Some medical experts claim that wearing a face mask is harmful to the wearer. Not only does it not protect you, they say, but it can limit your oxygen and even redirect harmful pathogens that you may be carrying back into your airway. As COVID-19 lockdowns end and people are getting out in the public again, what does the evidence say about wearing masks?
Advice From WHO and CDC About Face Masks Differs
The World Health Organization, founded in 1948, consists of more than 7,000 people from more than 150 countries. Its staff includes medical doctors, public health specialists, scientists, epidemiologists and experts in health statistics, economics and emergency relief. When it comes to masks for COVID-19, this body of experts does not cast masks as the panacea. Originally, the WHO listed these guidelines as to who should wear masks:
- If you are healthy, you only need to wear a mask if you are taking care of a person with COVID-19.
- Wear a mask if you are coughing or sneezing.
- Masks are effective only when used in combination with frequent hand-cleaning with alcohol-based hand rub or soap and water.
- If you wear a mask, then you must know how to use it and dispose of it properly.
The WHO changed its mind, though, and modified its recommendations June 5, 2020, to advise the general public to wear a mask in specific situations when social distancing isn’t possible. Otherwise, “… there is no direct evidence (from studies on COVID- 19 and in healthy people in the community) on the effectiveness of universal masking of healthy people in the community to prevent infection with respiratory viruses, including COVID-19.”
The Centers for Disease Control and Prevention is the U.S.’s leading health agency, administered under the Department of Health and Human Services. When it comes to battling COVID-19, its advice is not the same as WHO’s. Pointing out that people can carry the virus with no symptoms or before symptoms like coughing and sneezing surface, it wrote on its website April 3, 2020:
“This means that the virus can spread between people interacting in close proximity … CDC recommends wearing cloth face coverings in public settings where other social distancing measures are difficult to maintain (e.g., grocery stores and pharmacies) especially in areas of significant community-based transmission …
CDC is additionally advising the use of simple cloth face coverings to slow the spread of the virus and help people who may have the virus and do not know it from transmitting it to others.”
By May 22, 2020, the CDC had added a yellow-highlighted banner to its page, saying, “A cloth face covering may not protect the wearer, but it may keep the wearer from spreading the virus to others.”
Many medical and political leaders support wearing masks. Dr. Anthony Fauci, the high-profile medical member of the White House coronavirus task force and director of the National Institute of Allergy and Infectious Diseases, has endorsed them. So has former acting CDC director Dr. Richard Besser.
Virginia Gov. Ralph Northam signed an executive order at the end of May 2020 mandating masks in his state and Ohio Gov. Mike DeWine said wearing a mask is an expression of “loving your fellow human being.”
Countries that routinely use face masks have lowered their COVID-19 transmission. Does that mean those who reject face masks are increasing the risk of transmission to themselves and others? Many questions remain.
What Does Research Say About Face Mask Effectiveness?
Dr. Chris Murray, director of the Institute for Health Metrics and Evaluation, has said that face masks represent “probably a 50% protection against transmission,” but other estimates are less reassuring. For example, a study on the ability of masks to block COVID-19, which is caused by the SARS-CoV-2 virus, published by South Korean researchers in the Annals of Internal Medicine in April 2020, found:
“Neither surgical nor cotton masks effectively filtered SARS-CoV-2 during coughs by infected patients. Prior evidence that surgical masks effectively filtered influenza virus informed recommendations that patients with confirmed or suspected COVID-19 should wear face masks to prevent transmission.
However, the size and concentrations of SARS-CoV-2 in aerosols generated during coughing are unknown.
Oberg and Brousseau demonstrated that surgical masks did not exhibit adequate filter performance against aerosols measuring 0.9, 2.0, and 3.1 μm in diameter … assuming that SARS-CoV-2 has a similar size [to SARS–CoV], surgical masks are unlikely to effectively filter this virus.”
Contamination was found on the outside of the masks, wrote the researchers:
“Of note, we found greater contamination on the outer than the inner mask surfaces … The mask’s aerodynamic features may explain this finding. A turbulent jet due to air leakage around the mask edge could contaminate the outer surface. Alternatively, the small aerosols of SARS-CoV-2 generated during a high-velocity cough might penetrate the masks.
In conclusion, both surgical and cotton masks seem to be ineffective in preventing the dissemination of SARS-CoV-2 from the coughs of patients with COVID-19 to the environment and external mask surface.”
Criticism of the study by other researchers was brisk, ranging from questioning the handling of the masks before the experiment, which could have caused the observed contamination, to noting that only a small number of subjects were involved.
Paul W. Leu, an associate professor of industrial engineering, mechanical engineering and materials science at the University of Pittsburgh, noted in a letter to the editor that the premise of the research was wrong since masks are not intended to “shorten the trajectory of droplets emitted during coughing.” Instead, he wrote:
“The conclusions of this study … are not only erroneous but misleading … The function of the mask is to reduce how far aerosol droplets travel during breathing, speaking, singing, sneezing, or coughing. This is the same reason one should cover one’s mouth or nose with your forearm, inside of your elbow, or tissue when sneezing.”
Another critic, Ken Lim of CyberMedia Convergence Consulting, wrote that the experiment should have been “how many viral droplets appeared on another person or surface,” not on the masks themselves. Subsequently, in June, the authors retracted this study. Acknowledging that readers had called attention to flaws in their work, they said they had offered to correct it “with new experimental data from additional patients, but the editors requested retraction.”
More Questions About Face Mask Effectiveness
Research that appeared in April 2020 on medRxiv found that:
“The evidence is not sufficiently strong to support widespread use of facemasks as a protective measure against COVID-19. However, there is enough evidence to support the use of facemasks for short periods of time by particularly vulnerable individuals when in transient higher risk situations.”
However, Ian Jones, professor of virology at the University of Reading, disagreed with these findings, according to the journal BMJ. “If an aerosol droplet hits the weave of the mask fabric rather than the hole it is clearly arrested … helps to slow the epidemic,” he said, stating that masks are not a “cure” but are useful in flattening the curve.
Also according to BMJ, Simon Clarke, associate professor in cellular microbiology at the University of Reading, saw another problem with widespread wearing of masks. “Mass face mask wearing by the public would likely cause shortages among people who genuinely need protective equipment — health care workers on the front line in our hospitals,” he said.
According to the Mayo Clinic, even though masks are useful, the fear of a shortage of them shaped the CDC’s original recommendations. The clinic wrote on its website:
“The CDC acknowledged this concern when it recommended cloth masks for the public and not the surgical and N95 masks needed by health care providers.”
There was another reason for the CDC’s delay in endorsing masks when the pandemic first surfaced, wrote Mayo.
“At that time, experts didn’t yet know the extent to which people with COVID-19 could spread the virus before symptoms appeared. Nor was it known that some people have COVID-19 but don’t have any symptoms. Both groups can unknowingly spread the virus to others.
These discoveries led the U.S. Centers for Disease Control and Prevention (CDC) to do an about-face on face masks. The CDC updated its guidance to recommend widespread use of simple cloth face coverings to help prevent transmission of the virus by people who have COVID-19 but don’t know it.”
Another hurdle to a full endorsement of face masks by public health groups was the concern that they could provide a false sense of security. Experts also feared the masks could lead to more touching of the face or contamination if the wearer puts the mask down on an unclean surface.
When it comes to health care workers, they should not work without respiratory protection of some kind, according to the authors of a 2015 study who updated their comments in April 2020:
“There are now numerous reports of health workers wearing home made cloth masks, or re-using disposable mask and respirators, and asking for guidance. If health workers choose to work in these circumstances, guidance should be given around the use.
There have been a number of laboratory studies looking at the effectiveness of different types of cloth materials, single versus multiple layers and about the role that filters can play. However, none have been tested in a clinical trial for efficacy. If health workers choose to work using cloth masks, we suggest that they have at least two and cycle them, so that each one can be washed and dried after daily use.
Sanitizer spray or UV disinfection boxes can be used to clean them during breaks in a single day. These are pragmatic, rather than evidence-based suggestions, given the situation.
Finally for COVID-19, wearing a mask is not enough to protect healthcare workers — use of gloves and goggles are also required as a minimum, as SARS-CoV-2 may infect not only through the respiratory route, but also through contact with contaminated surfaces and self-contamination.”
Face Masks May Do Harm, Some Experts Say
The face mask controversy does not just revolve around whether they are effective or ineffective in preventing infections or whether widespread use would create shortages for health care professionals. Some medical experts say the masks can cause harm to wearers.
Virus expert Judy Mikovits of “Plandemic” fame has been very outspoken about the dangers of face masks. According to Weblyf.com, in social media posts she has written:
“Do you not know how unhealthy it is to keep inhaling your carbon dioxide and restricting proper oxygen flow? … The body requires AMPLE amounts of oxygen for optimal immune health. Proper oxygenation of your cells and blood is ESSENTIAL for the body to function as it needs to in order to fight off any illness. Masks will hamper oxygen intake.
Unless you are working in a hospital setting, it is NOT necessary … [If] [y]ou want to be healthy … Stop smoking, change your diet, stop consuming alcohol, turn off your wifi and cell phone, stop getting injected with neurotoxins, stop taking toxic medications, stop using so many chemicals … get some sun, drink plenty of (filtered) water [and] sleep well.”
Mikovits is not the only expert warning about face mask dangers. According to News-Medical.Net, Dr. Jenny Harries, England’s deputy chief medical officer, has warned the public against wearing facemasks “as the virus can get trapped in the material and causes infection when the wearer breathes in.”
Nationally recognized board-certified neurosurgeon Dr. Russell Blaylock also believes face masks are capable of causing serious harm:
“Now that we have established that there is no scientific evidence necessitating the wearing of a face mask for prevention, are there dangers to wearing a face mask, especially for long periods? Several studies have indeed found significant problems with wearing such a mask.
This can vary from headaches, to increased airway resistance, carbon dioxide accumulation, to hypoxia, all the way to serious life-threatening complications … By wearing a mask, the exhaled viruses will not be able to escape and will concentrate in the nasal passages, enter the olfactory nerves and travel into the brain.”
Face masks can also pose a danger to health care workers, wrote Blaylock, by causing “a reduction in blood oxygenation (hypoxia) or an elevation in blood CO2 (hypercapnia),” as well as headaches. The elderly are at risk, too, he warns:
“Unfortunately, no one is telling the frail elderly and those with lung diseases, such as COPD, emphysema or pulmonary fibrosis, of these dangers when wearing a facial mask of any kind — which can cause a severe worsening of lung function.
This also includes lung cancer patients and people having had lung surgery, especially with partial resection or even the removal of a whole lung.”
Face Shields May Be More Effective Than Face Masks
Face shields, plastic covers over the whole face that function as visors, may look extreme or “dorky” but they have some advantages over cloth masks. First, unlike cloth masks, they can be cleaned with soap and water or disinfectants and reused over and over because they are plastic and won’t degrade.
Second, face shields are more comfortable to wear, especially on hot days, since they are not placed directly over your mouth and nose and allow free breathing. Finally, and most importantly, face shields protect you better than face masks because the mouth and nose are not the only inlets of infection. According to the National Post, face shields also:
“… block the virus from entering ‘portals, (mouths, noses and eyes) and ‘reduce the potential for autoinoculation,’ meaning implanting the virus into our own bodies after touching a contaminated surface, by preventing the wearer from touching his or her face …
While SARS-CoV-2 is spread by breathing in tiny liquid virus-containing droplets, there is evidence it can enter the body through mucus membranes, including the mucus membranes on the surface of the eye and inner eye lids.”
Face shields, when studied with influenza, protected people from inhaling 96% of flu-laden droplets produced by a cough even when the face shield wearers were only 18 inches of someone coughing, the Post said. Clearly, they provide some of the protections of social distancing which may explain why we are increasingly seeing them used by health care practitioners.
If You Do Wear a Face Mask Follow These Guidelines
Clearly, there is evidence both for and against wearing face masks during the pandemic. If you do decide to wear a face mask, here are useful tips from WHO for usage and disposal to make sure you use your mask safely:
- Before putting on a mask, ideally clean your hands with soap and water.
- Cover your mouth and nose with the mask and make sure there are no gaps between your face and the mask.
- Avoid touching the mask while using it; if you do, clean your hands with alcohol-based hand rub or soap and water.
- Replace the mask with a new one as soon as it is damp and do not reuse single-use masks.
- To take off the mask: Remove it from behind (do not touch the front of the mask); discard it immediately in a closed bin; and clean your hands with alcohol-based hand rub or soap and water.