Since the coronavirus pandemic broke out, we have seen various versions of face masks people use to protect themselves against the virus, be it store-bought or homemade. But just how effective are these masks?

To find out, a Japanese chemistry professor compared three different types of face masks in a science experiment: a surgical mask, a homemade paper towel mask and a homemade cloth mask.

Dr Tomoaki Okuda, an associate professor of applied chemistry at Keio University, measured how well the three masks could block airborne particles using a Scanning Mobility Particle Sizer (SMPS).

To put it simply, the hose sucks the air in the room and measures its concentration of particles per cubic centimetre.

In his experiment, Okuda tuned the equipment to search for particles of virus size, which are estimated to be between 20 and 100 nanometers in diameter.

He wrapped the three masks around the opening of the hose and measured the number of air particles that were able to pass through. Here is a breakdown of his findings:

Surgical mask

With a store-bought surgical mask, the SMPS measured around 1,800 particles per cubic centimetre of air passing through. The results show that the mask has a collection efficiency of around 70 per cent, a high blockage rate for the estimated virus particle size.

Paper towel mask

Using three paper towels folded in half, Okuda tested a six-layer paper towel "mask". The SMPS measured around 1,000 particles per cubic centimetre of air passing through. With a collection efficiency of around 80 per cent, the paper towel mask appeared to be more effective in blocking out the estimated virus particle size compared to the surgical mask.

Cloth mask

A makeshift mask made out of a handkerchief folded thrice emulated the results of the surgical mask. The SMPS measured around 1,800 particles per cubic centimetre of air passing through, with a collection efficiency of around 70 per cent for the estimated virus particle size.

No mask

Additionally, Dr Okuda tested the hose without a mask covering it and the SMPS measured around 6,000 particles per cubic centimetre of air in the room that are between 10 and 150 nanometers in size.

So what does it mean? If we are near an infected person, there is potentially a lot of virus particles that we're breathing in.

[embed]https://www.youtube.com/watch?time_continue=11&v=T4fhfCUWFL4&feature=emb_logo[/embed]

Conclusion

Looking at the results, wearing a mask does seem to lower the chances of getting infected. Surprisingly, the mask fashioned from a handkerchief has the same effectiveness as a surgical mask, but even more so, who knew paper towels were the most effective?

However, regardless of which mask is the most effective, what's most important is to have good hygiene care and to wear masks properly. Here are also some tips on how to modify or wash your government-issued mask so that it can last longer.

For the latest updates on the coronavirus, visit here.

trining@asiaone.com