Commonly available home-made masks have been found to decrease the wearer’s risk of catching COVID-19.
A Flinders University study has found that even the poorest performing masks filtered at least 50 per cent of viruses.
The research team built a special apparatus to test a variety of masks and their ability to filter out tiny aerosol droplets of two different sizes: six microns, which is the size of droplets produced by coughing, and 2.6 microns, which are small enough to be inhaled into the lower respiratory system.
Then they chose masks at random from five home retailers advertising masks on the Etsy online marketplace.
The best performing fabric masks filtered 97 to 99 per cent of the droplets when made according to the Victorian Government’s guidelines, with two layers of reusable shopping bag fabric and one layer of cotton.
Another mask made from two layers of cotton was much less effective, with one result at just 55 per cent.
However, US modelling has shown that if 80 per cent of the population wore a 50 per cent effective mask in areas of high transmission, the number of COVID-19 deaths could fall between 17 per cent and 45 per cent.
Flinders University scientist Dr Harriet Whiley says the study provides useful guidance.
“The information will also inform best practice for fabric face mask design to protect against respiratory diseases and reduce community-based transmission,” she said.
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