Clicky

Researchers Find Leakage of Airborne Droplets Escaping From COVID Masks – Even When Just Breathing

Researchers Find Leakage of Airborne Droplets Escaping From COVID Masks – Even When Just Breathing

0 View

Publish Date:
7 May, 2021
Category:
Covid
Video License
Standard License
Imported From:
Youtube

The figure shows the breathing range without a mask and during various mask and face shield evaluations. Credit: Venugopal Arumuru / Indian Institute of Technology Bhubaneswar

Reducing the spread of coronavirus in confined spaces means better masks, adequate ventilation.

As research continues to show that the COVID-19 virus is transmissible via smaller droplets floating in the air, there is growing concern that current public health guidelines for mask wearing and social aloofness are insufficient to prevent its spread in indoor environments such as prisons, hospitals and meat packaging. plants, where people tend to be close.

Most of the research has focused on coughing and sneezing. But studies on how simply breathing can contribute to the spread of the virus in the air are rare.

In AIP Advances, by AIP Publishing, researchers at the Indian Institute of Technology Bhubaneswar show that social detachment is just as important as wearing a mask when people are just breathing indoors or participating in a normal conversation, even when there is no risk of coughing or sneezing. They also found that mask leakage in the same scenario presents a remarkable challenge to prevent the spread of the virus.

“Our findings demonstrate the need for good ventilation systems that account for the 5 to 10% atomized particle leakage that occurs in each breathing cycle as a way to reduce droplet concentration in enclosed spaces,” said author Venugopal Arumuru. “There is also a need for innovation in the mask design to reduce side and bottom droplet leakage while providing adequate facial comfort.”

In an experimental setup, a mechanical breathing simulator was connected to a four foot mannequin to simulate regular breathing and slightly longer breathing, typical of healthy adults standing still or engaged in moderate activities such as walking. talk or participate in assembly work. The researchers evaluated the efficacy of different mask types, mask-shield combinations, and only the use of face shields.

A mist generator was filled with a mixture of water and glycerine to simulate the consistency of saliva droplets in the diameter range of 1-10 micrometers to reflect air permeability. The droplet exposure was exposed and captured by a video camera.

The researchers found that without a face covering, droplets of the breath can travel up to 4 feet (4 m) within five seconds. A commercially available five-layer mask was found to provide the best protection, with full front protection and minimal leakage under the chin. A commercially available N-95 mask prevents front droplet leakage, but leakage in the gaps between the mask and the nose was significant.

Leakage from the front of the surgical mask was evident, although adding a face shield increased droplet restriction.

“The noticeable droplets that settle under the shield are alarming, however, and combining surgical masks with shields is not enough in hospitals and other places where strict social distance guidelines are difficult to follow,” Arumuru said.

Reference: “Respiration, Virus Transmission and Social Distance – An Experimental Visualization Study” by Venugopal Arumuru, Jangyadatta Pasa, Sidhartha Sankar Samantaray and Vaibhavsingh Surendrasingh Varma, April 6, 2021, AIP Advances.
DOI: 10.1063 / 5.0045582