We all know by now that wearing a face cover can help protect others from your germs, but there’s also evidence to suggest they might protect you as well.
A study from the University of Oxford’s Leverhulme Centre for Demographic Science found cloth face coverings, including homemade masks, are effective in reducing the spread of Covid-19. They are both effective for the wearer and those around them, said researchers.
Professor Melinda Mills, director of the Leverhulme Centre and author of the study, believes if more people understood wearing a mask could also protect themselves, it would increase people’s willingness to wear them.
“We found that the countries where mask use was the highest and most effective were the ones where people actually understood how masks work and that they protect the wearer and those around them,” she tells HuffPost UK.
“Understanding barriers, such as how to wear them, when and where to wear them and who cannot wear them, is key.”
Their analysis, conducted on behalf of the Royal Society and British Academy, looked at existing studies that have compared the protection of the wearer who wore a cloth mask compared to those who didn’t wear a mask.
“We looked at cloth masks and not surgical masks or respirators, since cloth face coverings is what is being advised for wearing by the general public,” says Prof Mills. In total, they found four studies that looked at wearing cloth face masks versus not wearing masks at all.
Wearing a cotton mask was associated with a 54% lower risk of infection compared to the no-mask group. “It is not 100% protective but does reduce your odds,” says Prof Mills, who does add that the studies were conducted in health care settings in relation to SARS and swine flu (H1N1), so cannot be directly applied to Covid-19.
The study concluded that clear and consistent policies and public messaging are key to the adoption of wearing face masks and coverings by the general public, which might go some way to explaining why uptake in the UK has been so low. A YouGov poll from June found under a quarter (21%) of Brits wear a mask or cover when out in public.
There’s plenty of evidence that DIY masks are useful at protecting the wearer, writes researcher Jeremy Howard in a separate report.
Effective protection depends on three “critical” things, says Howard. Firstly, material: does the mask filter particles of the appropriate sizes? Secondly, fit: could particles squeeze in through the gaps of your mask? And lastly, sanitation: can you clean and re-use the mask?
Prof Mills also looked at whether fabric and fit impacted protectiveness in her analysis and found the best face coverings were made from specific material such as high grade cotton or multiple layers, and needed to be fitted correctly.
Research on a variety of fabrics and patterns of face coverings has shown that tightly woven fabrics such as cotton, denim or tea cloths filter the best and that a combination of multiple layers is the most effective, while loosely woven fabrics like a scarf have been shown to be the least effective.
Attention must be placed on how well it fits on the face; it should loop around the ears or around the back of the neck for better coverage. Fit is super important regardless of what type of face cover you wear, as studies have shown that even if surgical masks have gaps at the sides or are not fitted correctly, they become less effective.
Doctors are increasingly keen for members of the public to wear masks to protect themselves and those around them. A recent British Medical Association survey revealed 86% of more than 5,000 doctors agreed that mask-wearing should be mandated.
Dr David Strain, clinical senior lecturer at the University of Exeter and chair of the British Medical Association’s medical academic staff committee, tells HuffPost UK there is “a fair amount of evidence” that masks do protect both the wearer and the population.
“Multiple studies have evaluated the filtration effects of cloth masks relative to surgical masks,” he says, pointing out that most household materials can filter out larger droplets from speech.
“It can be reasonably expected that a well made three-ply [three-layer] cloth mask would perform just as well as a surgical mask in preventing transmission,” he says.
In terms of how it benefits the wearer, homemade cotton masks have been able to filter out 60% of particles, compared to the 75% filtered by surgical masks, he says. “This would suggest neither would provide optimal protection to an individual, although each still do offer some protection from becoming infected.”
There have been worries that if people do wear face covers they may become complacent and not follow social distancing guidelines or wash hands – experts stress these measures need to be followed as well.
It’s also important to remember that some people cannot wear masks due to medical reasons, while others may be disadvantaged by mass mask-wearing, such as those dependant on lip-reading. For these individuals, moving to the safer distance of 2m and removing the mask in order to facilitate communication, or the use of masks with a clear panel are an alternative, suggests Dr Strain.
He concludes: “When faced with the risk of a disease that indiscriminately kills, as yet has no curative treatment, and is increasingly demonstrated to have long-term health impacts irrespective of the severity of the original infection, we need to take all the help we can get to minimise risk.”