Face covering reduces forward breath distance by 90 per cent

Wearing face coverings could reduce the spread of Covid-19, according to a new study by the University of Edinburgh.

Research has found wearing a face covering can reduce the forward distance of an exhaled breath by more than 90 per cent.

As the breath could contain small droplets of water, some of which may contain traces of the virus, experts have said covering up the mouth and nose could help combat Covid-19.

Scientists testing the effectiveness of seven different types of face coverings, including medical grade and home made masks, said they could all potentially limit the spread of coronavirus.

The Scottish Government advised people on 28 April to wear face coverings when leaving the house and entering enclosed spaces where maintaining social distancing is more difficult, such as on public transport or in supermarkets.

First Minister Nicola Sturgeon announced the change in policy at her daily briefing, with the new guidance recommending the use of coverings that are made of cloth or other textiles, such as a scarf, and not medical-grade masks.

The Scottish Government is not recommending the use of face masks for children under the age of two.

The UK government initially said face masks could not protect people, but it has revised its advice and is now recommending people wear face coverings where they cannot remain two metres apart in settings such as small shops and on public transport.

European countries including Italy and Germany have said people should wear masks in such settings.

Dr Felicity Mehendale, a surgeon at the Centre for Global Health at the University of Edinburgh’s Usher Institute, said: “It was reassuring to see the handmade mask worked just as well as the surgical mask to stop the wearer’s breath flowing directly forwards.

“This suggests that some handmade masks can help to prevent the wearer from infecting the public.”

But a team lead by engineers at the university found some masks enabled strong jets of air to escape from the back and sides.

Surgical masks and the tested handmade masks were found to limit the forward flow of a breath out but also generate far-reaching leakage jets to the side, behind, above and below.

Heavy breathing and coughing, in particular, were shown to generate intense backward jets.

Only masks that form a tight seal with the face were found to prevent the escape of virusladen fluid particles, the team said.

Dr Ignazio Maria Viola, of the University of Edinburgh’s School of Engineering, who co-ordinated the project, said: “I have generally been impressed by the effectiveness of all the face coverings we tested.

“However, we discovered that some face coverings allow the emergence of downward or backward jets that people are not aware of and that could be a major hazard to others around them.”

Dr Mehendale added: “The strong backward jets mean you need to think twice before turning your head if you cough while wearing a mask and be careful if you stand behind or beside someone wearing a mask.”

Last week the UK Government announced that they had agreed a deal with Scottish technology company Honeywell to manufacture 70 million face masks for frontline NHS workers.

The deal, the biggest UK order of its kind, will create 450 new jobs at the production site in Newhouse, North Lanarkshire.

FFP2 and FFP3 masks will be produced over an 18-month period at Honeywell’s site with production set to begin as early as July. Each month will see up to 4.5 million masks roll off the production line, ready for distribution to frontline NHS and social care workers.

Lothian MSP, Miles Briggs, said: “The use of a face mask to reduce the possible transmission of Covid-19 is apparent and now we have the science to back it up.

“As we move out of lockdown, measures such as people using face masks will be vital for keeping the R number down. This is a very worthwhile piece of research by the University of Edinburgh on the effectiveness of different face masks.”

At the start of the pandemic, which started in China, there was a rush to buy face masks in Hong Kong, where people remembertheimpactofsars.

Hong Kong suffered 298 deaths from SARS, second only to mainland China, but the territory has only reported four fatalities from Covid-19.

Walking around without a face mask in Hong Kong, Japan or South Korea is seen as irresponsible, and several US states are also now advising people to wear them when out and in public spaces.

The World Health Organisation say on their website that masks are effective only when they are being used in combination with frequent handcleaning with alcohol-based hand rub or soap and water.

They advise people that if they are wearing a mask, then they must know how to use it and dispose of it properly.