A website built by the University of Cambridge has been created to reveal the risk of coronavirus infection in indoor spaces.
The app has various customizable settings that include the level of ventilation, number of occupants and the level of activity and mask wear.
Everyone can use it to determine what risk they are taking in a room of virtually any size or type.
For each set of parameters, the site produces a graph showing the chance of infection over a given period, with the default being 09:00 to 17:00.
The website is called Airborne.cam and can be accessed here.
A website built by the University of Cambridge is programmed to show the risk of coronavirus infection in indoor spaces, and is used by the university to vet sites and make Covid-safe (stock).
The online tool shows that in an office of 30 people, which is 100 square meters with three meters high ceilings, there is a risk that someone could catch the virus from 09:00 to 17:00 if someone is infected and no one wears masks, 6.06 percent is (pictured))
The graph it creates, which shows the risk of infection of an individual, is calculated by a series of scientific comparisons described in a new study published in Proceedings of the Royal Society A.
Users can determine the room’s occupancy, type of mask and activity level. Mask settings do not contain any mask, surgical masks, N95 masks or cloth covers.
Activity level can also be changed, from sitting / breathing to heavy exercise.
Ventilation can also be changed, with six options ranging from poorly ventilated to industrial ventilation of hospitals.
The academics also built in room dimensions and a period that are taken into account in the comparison.
As part of their research, the scientists found that two people chatting freely in a poorly ventilated space while not wearing a mask poses a greater risk of infection than when one of them would cough.
If everyone wears a surgical face mask all day and takes an hour of lunch outside, it drops to the same 2.13 percent (pictured)
The photo shows the different settings that can be changed by users to calculate a specific level of individual risks for a space via the Airborne.cam website.
This is according to them because talking leads to exhalation of small droplets called aerosols that float in a confined space.
Without adequate ventilation, they can linger in the air, increasing the risk of someone inhaling them and then becoming infected.
However, a cough produces large droplets that are much heavier and are likely to descend to the nearest surface and not hang in the air.
“Our knowledge of the spread of SARS-CoV-2 in the air has developed at an incredible rate when you consider that it is only a year since the virus was identified,” said Dr. Pedro de Oliveira said.
‘There are different ways to approach this problem. In our work, we consider the wide range of respiratory droplets that people exhale to transmit different scenarios of airborne transmission – the first is the rapid spread of small infectious droplets over a few meters within a few seconds, which can happen inside and outside.
“Then we show how these small droplets can accumulate in indoor spaces in the long run, and how they can be softened with adequate ventilation.”
The free online tool shows that in an office of 30 people, which is 100 square meters, with three meters high ceilings, there is a risk that someone can catch the virus from 09:00 to 17:00 if one person is infected and no one wears masks is 6.06 percent.
If everyone in the office wears a surgical face mask all day and takes an hour of lunch outside, it drops to just 2.13 percent.
But if three people in an average-sized dining room (18 square meters) work with poor ventilation, and one person is infected, the risk of catching the virus in more than eight hours is 48.73 percent.
The calculations are based on the assumption that ‘hands are washed and that individuals are far apart – ie there is no risk of short-distance transmission by droplets / aerosol’.
The instrument is now actively used by the University of Cambridge, which has made it a prerequisite for high-risk spaces at the institution, enabling staff to set mitigating factors, such as reduced capacity or increased ventilation.
“The tool can help people use fluid mechanics to make better choices and adjust their daily activities and environment to suppress the risk, both for themselves and for others,” says co-author Savvas Gkantonas, who led the development. . of the app with Dr de Oliveira.
A similar tool was previously created by researchers across the Atlantic at MIT.
The instrument reveals that the size or type of room does not matter so much, but what type of masks the people wear in the room, and the ventilation system with which it is equipped, can dramatically turn the risks on or off.
In a standard room with a high ceiling of 8 feet and each wall about 15 feet long, ten suitable young people, all eager with surgical face masks, can sit there safely and talk normally for two hours when the windows are closed due to the cold temperatures outside. .
But for a family of ten, some of whom are elderly, in a standard dining room for dinner where no one wears a mask because they eat and the windows are closed because it’s cold outside – and there are some heated discussions with raised voices – the instrument shows that the safe limit is lowered to just three minutes.
The developers say that the online site enables people to calculate risks with more nuances than the simple, and often vague, guidance to form ‘bubbles’ or social distance.
Calculations informing the site were published by authors John Bush and Martin Bazant on the pe-print server medRxiv.
The institutions of the MIT instrument for homes, schools and restaurants suggest that some people are probably safe for days in a house with more space or hours in a restaurant – but once the rooms are more densely occupied, the risk goes on