Back to Africa Check

Wear a mask, save lives – and ignore false advice

This article is more than 3 years old

Face masks threaten your health and won’t protect you from the new coronavirus, claims a graphic widely shared on Facebook, Instagram and WhatsApp in African countries since June 2020.

Its error-riddled text claims masks decrease “the amount of oxygen we need to live and be healthy”. A mask also “increases toxin inhalation” because “exhaled toxins are trapped in the mask” and so “re-inhaled into the lungs”.

This weakens the immune system and “encourages triggering and infection from dormant retroviruses”.

And the coronavirus is so small a mask won’t stop it, the graphic claims. It’s the “equivalent of using a chain link fence to keep mosquitoes away”. 

The graphic’s final point is that the effectiveness of masks hasn’t been studied. “Absolutely no peer-reviewed studies have been carried out of the mask effectiveness within a social environment to control, prevent, or eliminate the spread of disease.”

In April, Kenya and Nigeria made it compulsory for people to wear face masks in public, or face penalties. South Africa followed on 12 July, when president Cyril Ramaphosa announced that wearing masks, previously only encouraged, would now be enforced.

The World Health Organization (WHO) says masks are “part of a comprehensive package of the prevention and control measures that can limit the spread” of Covid-19.

But are masks in fact useless and dangerous? We checked. 

Busting mask myths

A special section of the WHO website busts myths about Covid-19. One myth is that masks decrease oxygen intake or increase the intake of exhaled carbon dioxide, so increasing “blood acidity”.

“The prolonged use of medical masks can be uncomfortable. However, it does not lead to CO2 intoxication nor oxygen deficiency,” the WHO says. 

“While wearing a medical mask, make sure it fits properly and that it is tight enough to allow you to breathe normally.”

Prof Donald Milton of the University of Maryland’s public health school leads an aerobiology and virology laboratory.

“There is no toxin intake from wearing a mask – if anything it decreases exposure to air pollution a little bit,” Milton told Africa Check.

“There is no increase in the ‘intake’ of carbon dioxide. There is very little carbon dioxide in outdoor air and, even indoors, the amount of carbon dioxide in the air is one-tenth or less than the amount in expired air.”

He added: “For people with chronic lung disease who have trouble breathing, the work of breathing through a mask might cause them to not breath enough. But that is a different issue.”

Milton is one of 240 experts who pushed the WHO to reconsider its guidance on the airborne transmission of the new coronavirus. 

He added it was inaccurate to say that wearing a face mask shuts down or weakens the immune system because they cause us to breathe in more carbon dioxide and toxins.

Many studies on mask effectiveness

And Milton said “many” studies had found masks to be effective against the coronavirus.

“Our papers in PloS Pathogens (2013) and our recent paper in Nature Medicine (2020) showed that masks block more than half of all influenza and most coronavirus aerosols shed into breath when worn by cases,” he told Africa Check.

A 5 June WHO advisory says studies of the flu, flu-like illnesses and human coronaviruses “provide evidence that the use of a medical mask can prevent the spread of infectious droplets from a symptomatic infected person ... to someone else”. Masks also prevent infection-carrying droplets from contaminating the environment around the infected person.

And, the WHO says, a recent meta-analysis of these studies shows that disposable surgical masks and reusable 12- to 16-layer cotton masks are “associated with protection of healthy individuals within households and among contacts of cases.”

A study published in the Lancet on 1 June also concluded that wearing face masks while also observing other Covid-19 preventive measures recommended by medical experts were crucial in preventing the spread of the virus. 

“Face mask use could result in a large reduction in risk of infection with stronger associations with N95 or similar respirators compared with disposable surgical masks or similar reusable 12 to 16 layer cotton masks,” it reports.

Protect yourself, protect others

Another study, Respiratory virus shedding in exhaled breath and efficacy of face masks”, published in Nature Research on 3 April, found that face masks could prevent the transmission of human coronaviruses by filtering respiratory droplets. 

“Surgical face masks significantly reduced detection of influenza virus RNA in respiratory droplets and coronavirus RNA in aerosols, with a trend toward reduced detection of coronavirus RNA in respiratory droplets,” it says.

“Our results indicate that surgical face masks could prevent transmission of human coronaviruses and influenza viruses from symptomatic individuals.”

Still confused about masks? The University of California in the US has produced a summary of the science behind why they are essential in slowing the spread of coronavirus.

Masks don’t only protect you from Covid-19. If you’re infected with the coronavirus, they protect the people around you as well. 

Republish our content for free

We believe that everyone needs the facts.

You can republish the text of this article free of charge, both online and in print. However, we ask that you pay attention to these simple guidelines. In a nutshell:

1. Do not include images, as in most cases we do not own the copyright.

2. Please do not edit the article.

3. Make sure you credit "Africa Check" in the byline and don't forget to mention that the article was originally published on

Add new comment

Restricted HTML

  • Allowed HTML tags: <a href hreflang> <em> <strong> <cite> <blockquote cite> <code> <ul type> <ol start type> <li> <dl> <dt> <dd> <h2 id> <h3 id> <h4 id> <h5 id> <h6 id>
  • Lines and paragraphs break automatically.
  • Web page addresses and email addresses turn into links automatically.
limit: 600 characters

Want to keep reading our fact-checks?

We will never charge you for verified, reliable information. Help us keep it that way by supporting our work.

Become a newsletter subscriber

Support independent fact-checking in Africa.