A recent simulation by a Japanese supercomputer shows that plastic face shields are not at all helpful when it comes to trapping respiratory aerosols, thus raising questions on their effectiveness in preventing the spread of novel coronavirus.Also Read - UK Exempts Vaccinated US, EU Travellers From Compulsory Quarantine; India Still on Red List

According to Fugaku, the world’s fastest supercomputer, almost 100 per cent of airborne droplets smaller than 5 micrometres were able to escape through plastic visors, which have been frequently used by people working in service industries. One millionth of a metre constitutes one micrometre. Also Read - Complete Lockdown in Kerala on THESE Dates Due to Rising Covid Cases. Check Details

The simulation took into account air flow and production of thousands of droplets of varying sizes to ascertain the role of face shields in protection against COVID-19. Also Read - SL vs IND 2021: Second T20I to go Ahead as Scheduled, Shikhar Dhawan Available

In addition, about half of larger droplets measuring 50 micrometres found their way into the air, according to Riken, a government-backed research institute.

Aerosol transmission and ventilation are major factors in the transmission of coronavirus, aside from hand-washing and sanitisation .

Makoto Tsubokura, team leader at Riken’s centre for computational science, said the simulation combined air flow with the reproduction of tens of thousand of droplets of different sizes, from under 1 micrometre to several hundred micrometres.

“This is especially true for small droplets of less than 20 micrometres,” Tsubokura told the British media daily The Guardian.

Small particles were able to escape through the gap between the face shield and the face.

Tsubokura suggested that people who are advised not to wear masks, such as those with underlying respiratory problems and small children, could wear face shields instead, but only outdoors or in properly ventilated indoor settings.

Plastic face visors have become a common sight as global economies reopen and functioning across all sectors resumes.

Fugaku had also recently discovered that face masks made from non-woven fabric are more effective at blocking the spread of Covid-19 via airborne droplets than those made of cotton and polyester.