Containing the spread of coronavirus in enclosed spaces means we need better masks and adequate ventilation. As research increasingly shows that the COVID-19 virus is spread through smaller droplets suspended in the air, concerns have grown that current public health guidelines that wearing masks and social distancing are not enough to stop it Transmission in indoor settings, such as prisons, hospitals and meatpacking plants, where people are often in closed and too close environments.
Most research on the spread of COVID-19 has focused on coughing and sneezing. But little research has been done on how simple breathing causes the virus to spread through the air.
In AIP Advances, published by AIP, IIT Bhubaneswar researchers show that when people indoors are simply breathing or engaging in normal conversation, even if there is no risk of coughing or sneezing, social Distance is just as important as wearing a mask. They also found that under the same circumstances, mask leakage was a significant challenge in preventing the spread of the virus.
"Our findings suggest that a good ventilation system is needed to reduce droplet concentrations in enclosed spaces by taking into account the 5% to 10% of aerosol particle leakage that occurs during each breathing cycle ," said author Venugopal Arumuru. "At the same time, innovations in mask design are required to reduce droplet leakage from the sides and bottom, while providing adequate facial comfort."
In an experimental setup, a mechanical breathing mock machine was attached to a mannequin 5 feet 8 inches tall to simulate healthy adults standing still or engaging in moderate activities such as walking, talking, or participating in assembly Regular breathing and slightly longer breathing characteristic of work). The researchers evaluated the efficacy of various mask types, mask- shield combinations, and the use of shields alone.
An atomizer is filled with a mixture of water and glycerol to simulate the consistency of saliva droplets in the 1-10 micron diameter range to reflect airborne transmissibility. The droplets were exposed to light and filmed by a video camera.
Researchers have found that droplets produced by breathing can travel 4 feet in 5 seconds without face occlusion. The researchers found that medical five-ply masks provided the best protection, adequate protection of the face, and less leakage below the chin, N95 masks hindered the leakage of droplets in the front, but the gap between the mask and nose The leak of gap is still very serious. The leakage in front of the common medical surgical mask is obvious. However, adding another mask can increase the spread of droplets. The situation of cotton masks is even worse, and the droplets can be directly penetrated. This experimental evidence suggests that surgical masks and protective face shields alone are not enough in hospitals and other places where strict social distancing guidelines are difficult to follow.
