The Indian scientists have found use of N95 masks as the most effective measure in curbing the spread of COVID19.
According to a study published in the journal ‘Physics of Fluids’, airborne transmission of respiratory aerosol droplets produced during coughing is one of the primary means of spreading of diseases like COVID19.
Padmanabha Prasanna Simha, a scientist from ISRO, and Prasanna Simha Mohan Rao from Sri Jayadeva Institute of Cardiovascular Sciences and Research in Karnataka, used technique called schlieren imaging, which visualises changes in density, to capture pictures of voluntary coughs from five test subjects.
The researchers found that N95 masks are the most effective tool to reduce 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.
Meanwhile, a disposable surgical mask greatly reduces this distance to between 0.5 m and 1.5 m, the study 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,” a report quoted Simha as saying.
“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,” he added.
According to the study, the airflow from coughs is found to be capable of traversing at least 1.5 to 3.0 meters without masks.
“It was also observed and confirmed that a long sleeve that covers the elbow substantially reduces the ejection of the cough airflow into the environment compared to coughing into a bare elbow,” the study stated.
It also emphasizes the simultaneous need for face masks and adequate social distancing.
The researchers added that a cough is able to leak through any openings and propagate in many directions.
“Adequate distancing is something that must not be ignored, since masks are not foolproof,” Simha added.
Meanwhile, India on Wednesday recorded a total of 32.34 lakh COVID19 cases with 67,151 more people testing positive for the infection in a day.
The COVID19 death toll in India climbed to 59,449 with 1,059 new fatalities being reported in a span of 24 hours.