A post on Instagram claims that “masks do nothing but limit oxygen and increase risk of bacteria and illness”, warning parents not to put masks on their children.
The post contains a quote from Dr Brian Lamb, a doctor based in Pittsburgh, US, who was interviewed by a local news station in June 2020 about mask wearing in warm weather. It is true, as the post states, that he said: “The heat and humidity build up in your mask and make a beautiful breeding ground for bacteria.”
However, it’s important to note that Dr Lamb was not advocating against mask wearing. In the same interview, he says people wearing cloth masks should wash them daily, and sets out situations in which they can reasonably be removed such as when exercising.
A young child is pictured wearing a mask in the post. Children under the age of 11 in England and Wales are exempt from wearing a mask in any setting, while children under the age of 12 are exempt in Scotland and children younger than 13 are exempt in Northern Ireland. In America, the US Centers for Disease Control and Prevention recommends that children over the age of two wear a mask in indoor public places.
Masks offer protection from Covid-19
The post’s claim that “masks do nothing” is incorrect. As we have written before, masks do reduce the risk of contracting Covid-19, to some extent.
The website of the scientific journal Nature has previously reported that studies show masks can reduce the viral dose someone might receive, and can help protect others by reducing the amount of virus exhaled if the wearer has an infection.
A recent meta analysis (where a number of studies are analysed collectively) in the British Medical Journal also showed that mask wearing, alongside other precautionary measures like social distancing and hand washing, was associated with a reduction in risk. However, as we’ve written before, experts have urged caution in interpreting these results due to potential confounding factors.
It is recommended that fabric face masks or face coverings should be made of breathable material, be at least two to three layers thick and be well secured.
The Department of Health and Social Care says: “The best available scientific evidence is that, when used correctly, wearing a face covering may reduce the spread of coronavirus droplets, helping to protect everyone.”
Face masks don’t limit oxygen intake
The claim that face masks limit oxygen intake is untrue, and has been widely debunked as such.
Paper and cloth masks are permeable to air—meaning oxygen and carbon dioxide are able to flow as normal during the respiratory process—but they restrict the movement of water droplets we exhale or sneeze (potentially containing viral matter).
The British Lung Foundation says: “Wearing a mask does not reduce a person’s oxygen supply or cause a build-up of carbon dioxide. You may have read stories that say that it can, but this isn’t true.”
Bacteria and face masks
Bacteria can collect on face masks, as they can on many other surfaces. Scientists and public health experts such as the World Health Organisation have emphasised the importance of maintaining proper hygiene around mask wearing throughout the pandemic.
Single-use masks should not be reworn, and reusable cloth masks should be washed after every use.
Full Fact, as well as other fact checkers at Reuters and Associated Press, have addressed claims that face masks can cause infections such as bacterial pneumonia previously during the pandemic.
There is no evidence that normal mask-wearing increases the risk of contracting bacterial pneumonia.