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Scientists have criticised the government for its mixed messaging about wearing face masks during the pandemic, and a number of ministers have been seen wearing them in public - so what does the science actually say?
Prime Minister Boris Johnson has said Britons should be
wearing face coverings in shops
because they offer a "great deal of value" in controlling the spread of **coronavirus
.**
Meanwhile, cabinet minister Robert Jenrick claimed "people are still learning how to use face coverings" after Home Secretary Priti Patel was pictured wearing a mask when meeting her French counterpart outside - but
not wearing one when they spoke indoors
.
Lancet study backs distancing and face masks
Currently, the official UK government guidance states that evidence around wearing a face covering suggests it "does not protect you" from coronavirus.
But the guidance adds: "If you are infected but have not yet developed symptoms, it may provide some protection for others you come into close contact with."
The evidence of coverings preventing the spread of infection from one person to another is "marginal but positive", according to the Scientific Advisory Group for Emergencies that is advising the government.
But a study by Cambridge University says even basic homemade masks can reduce transmission - and could even help to
prevent a second wave
.
It said population-wide use of masks would keep the COVID-19 reproduction number (R rate) below one.
Surgical face masks 'make a big difference'
An international report published in The Lancet, which analysed data from 172 studies in 16 countries, found that by wearing a face mask
there is just a 3% chance
of catching COVID-19.
Another study found that
homemade face masks can help limit the spread
of the coronavirus.
Seven types of face masks were put to the test by the University of Edinburgh, including surgical masks, respirators, lightweight and heavy-duty face shields, and handmade masks.
Aside from those with a valve, all of the face coverings were found to reduce the forward distance travelled by an exhaled breath by at least 90%.
The growing industry of DIY face masks
However the World Health Organisation (WHO) has stressed that masks "on their own" will not protect from COVID-19.
It says there is no evidence that wearing one - whether medical or other types - by healthy persons in the wider community can prevent them from being infected with respiratory viruses, including the coronavirus.
Fears have also been raised that they could give people a false sense of security and mean they are less observant of the rules around social distancing and hand hygiene.
The government's official advice states that surgical masks should be reserved for people who need them for protection while at work.
It encourages people to make face coverings at home, saying "the key thing is it should cover your mouth and nose".
