With new knowledge on the transmission of COVID-19 through aerosols, the government should release an advisory asking people to wear good quality masks while stepping out of their houses. They must educate people on the importance of wearing masks, the kind of masks to be used and the right way to wear them, said Sundeep Salvi, director, Pulmocare Research and Education Foundation, Pune.
“Awareness should be the first step. People in countries like Korea and Japan wear masks irrespective of whether there is COVID-19 or not. The spread of COVID-19 in these countries has been very slow. These were the least-affected countries. I believe the main reason was the habit among its people of wearing masks. This has to become a culture within the country. It is a big cultural change,” he said.
He was speaking at a webinar on ‘Droplet versus airborne transmission of SARS-CoV-2: updated guidance on mask use’ on Monday.
If most people in a community wear masks, can the spread of COVID-19 be halted? “The answer is yes, and there is evidence from at least two big studies. These are mathematical models in the U.S. and they have clearly shown that a simple thing like wearing masks can reduce the load of COVID-19 by 50%-80%,” he said.
He said that wearing masks prevented the risk of transmission and protected one from being infected.
He noted that 239 scientists from 32 countries had supported the commentary on the airborne transmission of COVID-19, challenging the World Health Organization to change its advisory that there was not just a droplet route of transmission but also an aerosol one.
“This requires a different set of public health measures such as ventilation. Physical distancing of 2 m is not enough and everybody has to wear masks,” he added.
Both droplets and aerosols travel through air but have different properties in terms of remaining suspended in the air and the distance they travel, he said.
Droplets and aerosols
In terms of size, any particle more than 10 microns in diameter is a droplet and they can remain suspended in the air for about one to three minutes and the distance travelled is 1 m - 2 m.
If the particle is less than 10 microns in diameter, it is called an aerosol. These particles can remain suspended in the air for a longer period of time than the droplets, and the distance travelled is more than 10 m.
A good quality mask does not mean an N95 mask or a surgical mask, he noted. Both surgical masks and N95 masks should be worn just once, and then disposed, while cloth masks are washable, cheap and easily available, he added.
The webinar was organised by Internews.