Homemade masks CAN reduce the spread of coronavirus: Video shows how face coverings cut the distance saliva droplets travel forward by 90 per cent but allow ‘strong jets of air’ to escape around the sides
- Researchers studied multiple types of facemasks to test how effective they were
- They looked at medical grade and homemade masks as part of the research
- Authors found all of the masks could potentially limit the spread of COVID-19
- Here’s how to help people impacted by Covid-19
Homemade face masks can help slow the spread of coronavirus but still let strong jets of air escape from the sides, a new study shows.
Researchers from the University of Edinburgh found that wearing face coverings can reduce the forward spread of saliva 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.
The Edinburgh team tested the effectiveness of seven different types of face coverings, including medical grade and home made masks,.
Study authors said they could all potentially limit the spread of coronavirus.
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
The Scottish Government advised people on April 28 to wear face masks while out of the home, with the UK Government making the recommendation on May 11.
Neither have made the policy mandatory but some shops, including Apple Stores are requiring the masks for customers in store and even providing them.
Dr Felicity Mehendale, a surgeon at the Centre for Global Health at the University of Edinburgh’s Usher Institute, said the findings were reassuring.
She 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’ said Mehendale.
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 that then escape out of the sides of the mask.
Only masks that form a tight seal with the face were found to prevent the escape of virus-laden fluid particles, the team said.
The Scottish Government advised people on April 28 to wear face masks while out of the home, with the UK Government making the recommendation on May 11
Dr Ignazio Maria Viola, of the University of Edinburgh’s School of Engineering, who co-ordinated the project, said he was generally impressed with the coverings.
‘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,’ he said.
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.’
The team also discovered that a regular medical procedure known as extubation – the removal of a breathing tube used during anaesthesia and when patients are on a ventilator – may increase the risk of spreading Covid-19.
Simulations showed that the coughing that regularly accompanies extubation caused people nearby to be enveloped in the patients’ exhaled air.
This puts clinicians and others at high risk of exposure to the virus.
Professor Paul Digard Chair of Virology, the Roslin Institute said being able to visualise where breath or coughs go is a reasonable proxy for virus transmission.
‘The findings of this important study measuring the effectiveness of various professional and homemade face coverings show that masks generally reduce forward air flow, but coughing through a loose-fitting mask can lead to jets of air in unexpected directions.
‘This means that masks are likely to help, but it’s important to maintain the two meter social distancing.’
DO FACE MASKS MAKE A DIFFERENCE AND WHAT SHOULD YOU WEAR IF YOU CAN’T GET ONE?
Americans are increasingly being spotted wearing face masks in public amid the coronavirus pandemic, as are people are around the globe.
Soon, the Centers for Disease Control and Prevention (CDC) may advise all Americans to cover their faces when they leave the house, the Washington Post reported.
The agency is weighing that recommendation after initially telling Americans that they didn’t need to wear masks and that anything other than a high-grade N95 medical mask would do little to prevent infection any way.
FACE MASKS DO HELP PREVENT INFECTION – BUT THEY’RE NOT ALL CREATED EQUAL
Research on how well various types of masks and face coverings varies but, recently, and in light of the pandemic of COVID-19, experts are increasingly leaning toward the notion that something is better than nothing.
A University of Oxford study published on March 30 concluded that surgical masks are just as effective at preventing respiratory infections as N95 masks for doctors, nurses and other health care workers.
It’s too early for their to be reliable data on how well they prevent infection with COVID-19, but the study found the thinner, cheaper masks do work in flu outbreaks.
The difference between surgical or face masks and N95 masks lies in the size of particles that can – and more importantly, can’t – get though the materials.
N95 respirators are made of thick, tightly woven and molded material that fits tightly over the face and can stop 95 percent of all airborne particles, while surgical masks are thinner, fit more loosely, and more porous.
This makes surgical masks much more comfortable to breathe and work in, but less effective at stopping small particles from entering your mouth and nose.
Droplets of saliva and mucous from coughs and sneezes are very small, and viral particles themselves are particularly tiny – in fact, they’re about 20-times smaller than bacteria.
For this reason, a JAMA study published this month still contended that people without symptoms should not wear surgical masks, because there is not proof the gear will protect them from infection – although they may keep people who are coughing and sneezing from infecting others.
But the Oxford analysis of past studies – which has not yet been peer reviewed – found that surgical masks were worth wearing and didn’t provide statistically less protection than N95 for health care workers around flu patients.
However, any face mask is only as good as other health and hygiene practices. Experts universally agree that there’s simply no replacement for thorough, frequent hand-washing for preventing disease transmission.
Some think the masks may also help to ‘train’ people not to touch their faces, while others argue that the unfamiliar garment will just make people do it more, actually raising infection risks.
If the CDC does instruct Americans to wear masks, it could create a second issue: Hospitals already face shortages of masks and other PPE.
WHAT TO USE TO COVER YOUR FACE IF YOU DON’T HAVE A MASK
So the agency may recommend regular citizens use alternatives like cloth masks or bandanas.
‘Homemade masks theoretically could offer some protection if the materials and fit were optimized, but this is uncertain,’ Dr Jeffrey Duchin, a Seattle health official told the Washington Post.
A 2013 study found that next to a surgical mask, a vacuum cleaner bag provided the best material for a homemade mask.
After a vacuum bag, kitchen towels were fairly protective, but uncomfortable. Masks made of T-shirts were very tolerable, but only worked a third as well as surgical mask. The Cambridge University researchers concluded that homemade masks should only be used ‘as a last resort.’
But as the pandemic has spread to more than 164,000 people worldwide, it might be time to consider last resort options.
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