At a time when universities and schools around the world are looking to reopen, a recent study indicates that masks and good ventilation systems may be better, and more important, at containing the COVID-19 which is spreading this social distancing, in a space closed.
The research has been published in the peer-reviewed scientific journal Fluid physics and focuses on a classroom setting where the presence of a good ventilation system and the use of masks were studied. The researchers created a computer model of a classroom that included students and a teacher. They then modeled the pattern of air circulation in the room and disease transmission. With these, the researchers were able to estimate the risk of airborne transmission posed by COVID-19.
However, a few caveats here. The study covers certain dimensions of parts with air filters. It may not be applicable in smaller rooms with a larger number of students or people in a room, with or without adequate ventilation, as may be the case in India.
It is well known that COVID-19 is spread via airborne particles caused by sneezing, coughing, or an infected person talking. Airborne particles containing the virus are inhaled by another person and transmission occurs as well.
An important part of the study was the model classroom, which measured 9.5m long and 7.0m wide with a height of 2.7m. The model had students with masks (anyone among them could be infected) with the masked teacher as well.
The researchers then analyzed the airborne transmission based on two situations. The first case involved the well ventilated classroom, while the other was not. The study took into account two computational approaches used in studies of fluid dynamics. The first is known as the Wells-Riley approach, where the probabilities of interior transmission of fluid particles (such as air particles) are studied while the other is computational fluid dynamics, commonly used to understand the aerodynamics of cars, airplanes or the movement of submarines underwater. .
Commenting on the study, Michael Kinzel, study co-author and assistant professor at the University of Central Florida, was cited saying: “Research is important because it provides guidance on how we understand safety in indoor environments (sic). “
Wearing masks has been shown to be beneficial in preventing transmission because masks provide a weak puff of warm air due to breathing and aerosols can then travel vertically. This movement of the aerosols (containing the virus particles) prevented them from reaching the adjacent pupils.
“The study reveals that aerosol transmission routes do not require a six-foot social distancing when masks are mandatory. These results show that with masks, the likelihood of transmission does not decrease with increased physical distance, this which underlines just how essential mask mandates can be in schools and elsewhere, ”he would have said.
In addition, a good ventilation system with an air filter reduces the risk of infection by 40% to 50% compared to classrooms without a ventilation source. A good ventilation system creates a steady flow of incoming and outgoing air and this air flow carries many aerosol particles (along with virus particles) to the air filter. The air filter removes some of the aerosols. In contrast, in a room without good ventilation, aerosols concentrate above the people inside the room.
Kinzel further Explain their results: “If we compare the odds of infection when wearing masks, three feet of social distancing did not indicate an increased odds of infection compared to six feet, which may provide evidence for schools and other businesses can operate safely during the remainder of the pandemic. The results suggest that ventilation systems and the use of masks are the most important in preventing transmission and that social distancing would be the first thing to relax (sic). “