Udayavni Special

Indian scientists find N95 masks to be most effective at stopping Covid-19 spread


Team Udayavani, Aug 26, 2020, 2:40 PM IST

New Delhi: N95 masks may be the most effective at reducing the spread of the novel coronavirus, according a study by researchers, including those from the Indian Space Research Organisation (ISRO), which suggests that any mask is better than no mask at preventing Covid-19.

The researchers noted that airborne transmission by respiratory aerosol droplets produced during coughing and sneezing is the dominant mode of spreading for infectious diseases such as Covid-19.

Padmanabha Prasanna Simha, from ISRO, and Prasanna Simha Mohan Rao, from the Sri Jayadeva Institute of Cardiovascular Sciences and Research in Karnataka, experimentally visualised the flow fields of coughs under various common mouth covering scenarios.

The study published in the journal Physics of Fluids, found N95 masks to be the most effective at reducing the horizontal spread of a cough.

The N95 masks reduced a cough’s initial velocity by up to a factor of 10, and limit its spread to between 0.1 and 0.25 meters, the researchers said.

An uncovered cough, in contrast, can travel up to three metres, but even a simple disposable mask can bring this all the way down to 0.5 metres, they said.

“If a person can reduce the extent of how much they contaminate the environment by mitigating the spread, it’s a far better situation for other healthy individuals who may enter places that have such contaminated areas,” Simha said.

Rao and Simha noted that density and temperature are intricately related, and coughs tend to be warmer than their surrounding area.

They utilised a technique called schlieren imaging, which visualises changes in density, to capture pictures of voluntary coughs from five test subjects.

By tracking the motion of a cough over successive images, the team estimated velocity and spread of the expelled droplets.

N95 masks have the best effectiveness and completely contain the horizontal spread to between 0.1 and 0.25 metres, researchers said.

A disposable surgical mask greatly reduces this distance to between 0.5 and 1.5 metres, they said.

“Even if a mask does not filter out all the particles, if we can prevent clouds of such particles from traveling very far, it’s better than not doing anything,” said Simha.

“In situations where sophisticated masks are not available, any mask is better than no mask at all for the general public in slowing the spread of infection,” said Simha.

The researchers also contradict the generally accepted notion that using an elbow to cover up a cough is a good alternative.

The found that unless covered by a sleeve, a bare arm cannot form the proper seal against the nose necessary to obstruct airflow.

The researchers added that a cough is able to leak through any openings and propagate in many directions.

Simha and Rao hope their findings will put to rest the argument that regular cloth masks are ineffective, but they emphasise that masks must continue to be used in conjunction with social distancing.

“Adequate distancing is something that must not be ignored, since masks are not foolproof,” Simha added.

Udayavani is now on Telegram. Click here to join our channel and stay updated with the latest news.

Top News

Met Dept forecasts thunderstorm in Udupi, DK and Kodagu dists on Monday evening

‘Variant of Concern’: All you need to know about the Indian variant of Covid-19

Police should show restraint in enforcing lockdown, says Min Bommai

Man left dangling from 330-foot glass bridge after strong winds shatter panels

COVID-19 vaccination drive for 18+ people begins in Dakshina Kannada

B’luru: Police stops auto rickshaw for checking; driver escapes with constable

DKShi asks govt to provide financial help to poor families



Related Articles More

Active COVID cases down by over 30,000 in 24 hours first time in 61 days: Health ministry

Prepare for the third wave of COVID-19: BSY to officials

Indian Covid strain ‘variant of concern’: WHO

M’luru, Udupi: COVID-19 death toll rises in DK; Udupi sees decrease in infections

Reports state China probed weaponising SARS‑CoV‑2 viruses in 2015

MUST WATCH

Karnataka’s first oxygen express to reach Whitefield

Kuwait ship carrying medical oxygen arrives at Navamangalore port

Dr Dinesh Shetty | Current Situation in Karnataka | Udayavani

Young man comes to buy vegetables wearing doctor’s apron

Unique Safety Method to save from Police

Latest Additions

Writer-actor Madampu Kunjukuttan dies of COVID-19

China warns of ‘substantial damage’ to relations if Bangladesh joins Quad

Active COVID cases down by over 30,000 in 24 hours first time in 61 days: Health ministry

Fmr Union Min Suresh Prabhu urges Sadananda Gowda to regulate prices, supply of Mucormycosis medicine

Met Dept forecasts thunderstorm in Udupi, DK and Kodagu dists on Monday evening

Thanks for visiting Udayavani

You seem to have an Ad Blocker on.
To continue reading, please turn it off or whitelist Udayavani.