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It’s inaccurate to say that wearing a face mask poses serious health risks

by Grailing Anthonisen - July 22, 2020   6327 Views   6 min
It’s inaccurate to say that wearing a face mask poses serious health risks


Wearing face masks poses serious health risks to the healthy


Inaccurate (no factual basis; unacceptable margin of error)

On the website “Technocracy”, Russell Blaylock, a retired doctor claimed that wearing face masks creates serious health risks for healthy people. This claim has no factual basis and is inaccurate. In addition, it is misleading.

A misleading title

In addition to the content of the article and its claim being inaccurate, the title is misleading as it does not mention the type of mask and for whom it is intended. For readers who only skim headlines and do not read full texts, the title could be interpreted as saying that masks are risky for healthy people. In fact, in the article, Blaylock focuses on N95 respirators, saying they cause a range of health problems, including headaches, hypoxia, and hypercapnia, which can lead to other illnesses like cancer.

While there is some evidence of headaches from the lengthy use of N95 respirators, which are meant to be reserved for medical professionals and not for the general population, there is no evidence or scientific basis for saying they pose serious health risks.

What type of mask?

Blaylock’s claims are mainly about N95 respirators, which are fitted to the face and filter at least 95% of particles. The general population should not be wearing these, as they should be reserved for frontline medical workers.

The claim does not directly address cloth masks, which the World Health Organization (WHO) recommends the general population wear. Surgical masks are loose-fitting and both surgical and cloth masks are porous, allowing air to be breathed in and out.

The evidence cited is either incorrect, mis-cited, or non-existent

One of the Blaylock’s assertion is that masks can cause hypoxia. This is when there is not enough oxygen in the blood. The study that Blaylock cites to make this claim never mentions hypoxia. Blaylock follows this up with statements like “it is known that the N95 mask, if worn for hours, can reduce blood oxygenation”, without any citation or source to explain how it is known or proven and by whom.

The American Lung Association rejects the claim that masks cause low oxygen levels, as masks are designed to be breathed through. They note that if you have pre-existing respiratory problems, you should discuss wearing a mask with your doctor. The US Centers for Disease Control and Prevention (CDC) also recommends that the people who should not wear a mask are those with trouble breathing, children aged two and under, and anyone who is unconscious, incapacitated, or unable to remove the cloth face mask on their own.

The study that Blaylock cites to claim that wearing a mask traps the virus near the face, causing people to re-inhale it and infect the brain through the nervous system, does not support his claims. The study in question is not about masks, but rather, examines mice and a viral strain of mouse hepatitis. Furthermore, the claim itself is illogical, because if a person exhales the virus, then they are already infected and cannot worsen their infection in this way.

If you are sick or think you are sick, the US CDC urges you to stay home unless it is to seek medical care. At home, if possible, you should stay in one room and away from other people in your home as much as possible. If you must be around people or animals, you should wear a cloth face mask.

N95 respirators may cause headaches, but not hypercapnia

Blaylock claimed that N95 respirators cause hypercapnia, which is increased CO2 in the blood, caused by re-breathing CO2 trapped in the mask. The World Health Organization is clear: “The prolonged use of medical masks can be uncomfortable. However, it does not lead to CO2 intoxication nor to oxygen deficiency”. A US CDC representative told Reuters that “CO2 will slowly build up in the mask over time. However, the level of CO2 likely to build up in the mask is mostly tolerable to people exposed to it. You might get a headache but you most likely [would] not suffer the symptoms observed at much higher levels of CO2. The mask can become uncomfortable for a variety of reasons including a sensitivity to CO2 and the person will be motivated to remove the mask. It is unlikely that wearing a mask will cause hypercapnia.”

Blaylock asserted that N95 respirators cause headaches in those who wear them. The US CDC notes that minor CO2 buildup and headaches can occur with possible long-term use of N95 respirators. They do not consider these to be serious health risks. To counteract this, they recommend simply removing the respirator in a safe place before putting it back on again. The benefits of wearing a N95 respirator for front line workers far outweigh the risks.

Are masks effective?

The US CDC cites increasing evidence of the effectiveness of masks to reduce the spray of infected droplets when worn over the nose and mouth. Because COVID-19 is mainly spread through close contact, face coverings are an important preventative measure, especially when physical distancing is not possible. The US CDC have reported that asymptomatic and pre-symptomatic people can spread COVID-19, which makes wearing a mask a preventative measure to reduce the risks of transmission.

WHO recommends that everyone else who is in public and cannot physically distance should wear a fabric mask. These situations include on public transportation and in shops, as well as areas where widespread transmission is known or suspected. WHO recommends wearing a medical-grade mask if you are 60 or older or have any underlying health conditions when you are in public and physical distancing is not possible.

Inaccurate and misleading claim and content

The claim we investigated, that face masks cause serious health risks to healthy people, is inaccurate. In addition, Blaylock makes several false claims about N95 respirators, which should be worn by medical personnel and not the general public. WHO recommends cloth masks for the general public and surgical masks for those over 60. These masks do not cause hypoxia or hypercapnia. Blaylock’s claims regarding rebreathing CO2 and headaches are overblown and can be easily countered by briefly removing the mask when in a safe place. Furthermore, the title of the article is misleading in that it does not specify the type of masks being studied nor the wearers for whom they are intended.

The author has a history of making false and pseudoscientific assertions

When looking at claims like these, it is important to look up trusted sources, like WHO or the US CDC to see their recommendations. If someone is making recommendations that contradict other advice from trusted sources, you can look up the person’s background, as, in the case of Blaylock, and see if they have a history of making claims and recommendations that go against scientific consensus. Even if someone is a doctor, they could still be a bad faith actor or not a specialist in the area they speak about, so it is important to be thorough. You can also look up the sources they cite for yourself. In this case, the sources did not back up what the author was claiming.

Sources lost in translation

This post has since been reproduced in portion in a Science Times article and translated into French on a blog. When reproduced, the sources, which are already problematic, are further degraded or lost. The French blog post is a translation of the original claims, but the sources that supposedly back up the claim are entirely different. Some lead to random tweets and many of them have no relation to the text. The Science Times, on one occasion, claims to cite a scientific study to support the claim that masks create serious health risks to wearers. It actually links to registration details of a clinical trial that ended in 2005. Results for this study do not appear to have ever been published.

Inaccurate pieces can gain more attention when being reposted or shared when their sources are not questioned or evaluated, even when they make less sense.

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The American Lung Association






Journal of Lung, Pulmonary & Respiratory Research

Journal of Virology

Previous history of Blaylock and misinformation:


Russell Blaylock

Wearing face masks poses serious health risks to the healthy


Inaccurate (no factual basis; unacceptable margin of error)

 July 22, 2020


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