Coronavirus could be ‘eradicated’ if 70% of people wore surgical or N95 masks in public – but cloth masks may not be enough to end the pandemic, study claims

• Researchers looked at three types of face masks: N95s, surgical masks and cloth masks  
• They found N95s were best for filtering out aerosol-sized droplets, which can remain suspended in the air for long periods of time
• While cloth masks are less effective, using a combination of fabrics rather than one type allows for best filtration and for heat to escape
• The team determined that the pandemic could be curbed if 70% of people wore face masks because the reproduction rate would fall below 1.0 

The coronavirus pandemic could be curbed if at least 70 percent of the public wore masks, a new study suggests.

Researchers looked at the physics of difference face coverings, including their material and designs.

They found that the three most common types of face masks – N95s, surgical masks and face masks – help lower reproduction (Rt) rates, meaning less people are being infected due to social distancing.

However, the team also found that only N95s were the most effective at filtering tiny infectious particles that can hang in the air for extended periods and burrow deep into the lungs.

A new study found N95s were best for filtering out aerosol-sized droplets, which can remain suspended in the air for long periods of time

For the study, published in the journal Physics of Fluids, the team looked at research on face masks and how they filter or block the virus.    

They analyzed how masks protect against fluid droplets that are expelled when a person coughs, sneezes, sings or even breathes. 

Larger droplets, which range between five to 10 microns – about seven times smaller than the diameter of a human hair – are the most common.

However, smaller droplets are perhaps more dangerous because they can become aerosolized and remain suspended in the air for long amounts of time.  

Among the three types of masks studies – N95s, surgical masks, cloths masks – solely N95s were found to filter out aerosol-sized droplets.

Researchers found that found masks made of hybrid polymer materials can filter particles and also cool the face.

This means using a mix of material for a face covering such as cotton, polyester, chiffon, silk, flannel.

When multiple layers were used, and a combination of different fabrics, it allows for best filtration and for heat to escape.

‘There could be some relation between breathing resistance and the flow resistance of the face mask which will need to be studied for a face mask-wearing interval,’ said said Dr Heow Pueh Lee, an associate professor of applied mechanics at the National University of Singapore.

‘Also, the environmental condition in the compartmental space within the face mask will need to be more accurately quantified using miniaturized sensors and the development of human replicas for such studies  

The study also found that regular use of face masks drop the Rt rate below 1.0.  

‘The results suggest that the consistent use of efficient face masks, such as surgical masks, could lead to the eradication of the pandemic if at least 70% of the residents use such masks in public consistently,’ said author Sanjay Kumar, an assistant professor of engineering as UC Berkeley.

‘Even less efficient cloth masks could also slow the spread if worn consistently.’  

It comes after former FDA commissioner Dr Scott Gottlieb wrote an op-ed in The Wall Street Journal, in which he encouraged American to buy better masks

Specifically he recommended the N95, or its equivalent, due to its proven ability to block at least 95 percent. of small particles

Gottlieb said the next best option is a surgical mask and, if nothing else is available, to buy cloth masks made from cotton-polyester blends.

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