Virus tests support use of fabric masks

Throughout the COVID-19 pandemic, Australians have been urged to wear masks in public, particularly those living in Victoria.

But if you’re making them at home, how do you know how efficient they are?

Researchers tested commonly available fabric masks and found even the worst performing masks filtered at least 50 per cent of virus particles carried through the air.

The study by Flinders University looked at the viral filtration efficiency (VFE) of a number of masks either bought off the internet or made at home.

Researchers challenged the masks by using a standard mask testing method with a model virus, called MS2, which is smaller in size than COVID-19.

Flinders University scientist Dr Harriet Whiley said while a 50 per cent reduction may not seem particularly effective, modelling studies suggested if 80 per cent of the population wore those masks in high transmission areas, the number of COVID-19 deaths could fall between 17 and 45 per cent.

“This would be even more improved in areas that you have lower transmission rates,” she said.

“The information will also inform best practice for fabric face mask design to protect against respiratory diseases and reduce community-based transmission of SARS-CoV-2 (the virus that causes COVID-19).”

The VFE was calculated for two sizes of aerosols – being 6 microns, which is the size of aerosols produced by coughing, and 2.6 microns, which is small enough to be inhaled into the lower respiratory system.

The best performing masks filtered 97 to 99 per cent of the virus numbers.

One mask, made with two layers of a shopping bag and one cotton layer according to Victoria’s health department standards, reduced viral particles by 98.6 per cent.

Another, which had a filtration level of 55 per cent on its own, increased to 98 per cent when a dried baby wipe was inserted.

The VFE improved further after adding a section of a vacuum cleaner bag to 99 per cent.

Co-author Associate Professor Kirstin Ross said further research was needed to test mask design and fitting.

“Fit is very important to reduce the risk of viruses entering through gaps between your face and the mask,” she said.

“There also should be an education campaign to inform people about how to wear fabric masks.

Dr Ross added it was important masks were worn correctly and should not be touched unless taking them off.

“Wash your mask after use in water that is hotter than 60°C with soap or laundry detergent.”

From August 2, every person living in Victoria had to wear a face covering when they left home.

Wearing a mask is not compulsory in NSW. However, NSW Health recommends people wear them when they can’t physical distance or are in high-risk indoor areas, such as on public transport, in supermarkets, shops, places of worship and entertainment venues.

With no current community transmission in Queensland, residents don’t need to wear masks unless they have been advised by their doctors.

South Australia’s Chief Public Health Officer Nicola Spurrier has advised residents to wear masks while travelling on planes, after it opens its borders to NSW on Thursday.

Residents in WA are living near-normal with low community transmission so masks are not a necessity.

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