It has been over a year now when people started wearing face masks to beat the deadly coronavirus. But people are still confused about whether these masks cut down the risk of transmitting and catching the coronavirus. While some prefer to wear medical masks, others opt for trendy fabric ones.
Medical masks are recommended for health workers in clinical settings. However, anyone who is feeling unwell including people with mild symptoms such as muscle aches, slight cough, sore throat, or fatigue can also use these masks. Non-medical fabric masks can be used by the general public under the age of 60 and who do not have underlying health conditions.
According to the World Health Organization (WHO), masks are a key measure to suppress transmission and save lives. WHO suggests that masks should be used as part of a comprehensive ‘Do it all!’ approach including physical distancing, avoiding crowds, closed and close-contact settings, good ventilation, cleaning hands, covering sneezes and coughs, and more. Depending on the type, masks can be used for either protection of healthy persons or to prevent onward transmission.
Many studies have revealed that a primary route of transmission of COVID-19 is via respiratory particles, and it is known to be transmissible from presymptomatic, paucisymptomatic, and asymptomatic individuals.
Reducing the spread requires limiting contacts of infected individuals via physical distancing and other measures including decreasing the transmission probability per contact. The preponderance of evidence indicates that mask-wearing decreases transmissibility by reducing transmission of infected respiratory particles in both laboratory and clinical contexts.
To be clear, the science supports using masks with recent studies suggesting that they could save lives in different ways: Research shows that they cut down the chances of both transmitting and catching the coronavirus and some studies indicate that masks might reduce the severity of infection if people do contract the disease.
There are several strands of evidence supporting the efficacy of masks. One category of evidence comes from laboratory studies of respiratory droplets and the ability of various masks to block them. An experiment using high-speed video found that hundreds of droplets ranging from 20 to 500 micrometers were generated when saying a simple phrase, but that nearly all these droplets were blocked when the mouth was covered by a damp washcloth. Another study of people who had influenza or the common cold found that wearing a surgical mask significantly reduced the amount of these respiratory viruses emitted in droplets and aerosols.
A recent study published in Health Affairs, for example, compared the COVID-19 growth rate before and after mask mandates in 15 states and the District of Columbia. It found that mask mandates led to a slowdown in the daily COVID-19 growth rate, which became more apparent over time. The first five days after a mandate, the daily growth rate slowed by 0.9 percentage-points compared to the five days prior to the mandate; at three weeks, the daily growth rate had slowed by 2 percentage points.
Another study looked at coronavirus deaths across 198 countries and found that those with cultural norms or government policies favouring mask-wearing had lower death rates.
As per a study published in the journal Physics of Fluids, researchers found that masks and a good ventilation system are more crucial and provides better results than social distancing for containing the airborne spread of COVID-19 infections indoors. The scientist prepared a computer model of a classroom with students and a teacher and then facilitated airflow and disease transmission, and calculated the risks of airborne transmission.
In the model, where the classroom was 709 square feet with 9-foot-tall ceilings, students were masked and the teacher at the front of the class also wore a mask.
“The study finds that aerosol transmission routes do not display a need for six feet social distancing when masks are mandated,” said Michael Kinzel, an assistant professor at the University of Central Florida in the US.
According to Kinzel, the research is important as it provides guidance on how we are understanding safety in indoor environments.
Similarly, the team of researchers evaluated a ventilated classroom and an unventilated one. The researchers found that a ventilation system with a good air filter minimized the risk of infection by 40 to 50 percent as compared to a classroom with no ventilation.
Studies and researches can differ but given the surge in COVID19 cases, wearing masks and maintaining social distancing is the need of the hour.
(Views expressed are author’s own. Feedback at syed.media@gmail.com)
