Written By: Longjam Dineshwori | Updated : August 11, 2020 10:10 AM IST
Wearing a face mask could stop up to 99 per cent of viral droplets before they reach someone else.
In the absence of a vaccine or antiviral medicine, wearing a face mask, frequent hand-washing, and social distancing, are considered to be the best preventive measures to slow the spread of the novel coronavirus. The new virus is transmitted through respiratory droplets released by infected an infected person while talking, sneezing, or coughing. Wearing a face mask is a simple and easy way to reduce the expulsion of respiratory droplets and protect others as well as yourself from COVID-19 the disease caused by the novel coronavirus. But how effective is your face mask in reducing the expulsion/prevention of viral droplets? Which types of face coverings are best in blocking expelled particles? Keep reading to clear your doubts.
Researchers from Duke University in the US have developed a new method to test the effectiveness of different types of masks in preventing the spread of droplets that could contain novel coronavirus particles. The developers believe that the new technique could help small scale mask producers to optimise designs, and help community outreach organisations demonstrate proper mask fitting procedures. The technique was described in the journal, Science Advances.
Using their new method, the scientists evaluated the effectiveness of 14 different types of masks and other frequently substituted face coverings, such as bandanas and neck fleeces. The test required the speakers to wear each mask while standing in a dark enclosure. Then the speakers were asked to say the phrase "stay healthy, people" five times in the direction of a laser beam, which scattered light from the droplets released during the speech. Using as a cell phone camera, the droplets are recorded and a simple computer algorithm counted them.
This 'simple and inexpensive' setup can be replicated by non-experts too, said the researchers. The hardware used here, including laser equipment, is easily available and can be purchased for less than USD 200.
Based on their preliminary, proof-of-principle findings, the researchers suggested that N95 masks without valves are best at blocking the droplets produced when wearers speak.
Surgical or polypropylene masks and handmade cotton masks are also effective in blocking droplet spread. But they observed more droplets expelled through bandanas and neck fleeces, suggesting that these materials may provide little protection against the novel coronavirus. This is because the materials use to bandanas and neck fleeces break up larger droplets as they pass through them, they explained.
However, the new method is still in the early stages of development and has so far only been tested in a small group of people. The researchers stressed the need for further testing to investigate variations in masks, speakers, and how people wear them.
They also want to extend their method to other droplet-generating actions, like coughing and sneezing, as well as explore the effects of incorrect placement and moisture saturation.
According to the Duke University researchers, about half of COVID-19 Infections are from asymptomatic patients, people who don't show symptoms. As these people often don't know they're infected, they can unknowingly spread the virus when they cough, sneeze and just talk. Wearing a face mask could stop up to 99 per cent of these droplets before they reach someone else.
But they noted that businesses who are engaged in supplying masks to the public and employees should have proper information about the products they're providing to assure the best protection possible.
