A website built by the University of Cambridge was created to reveal the risk of coronavirus infection indoors.
The application has various customizable settings, which include the level of ventilation, the number of occupants and the level of activity and wearing a mask.
Anyone can use it to find out the level of risk they take while in a room of almost any size or type.
For each set of parameters, the site produces a graph showing the chance of infection over a set period of time, the default value being from 9:00 to 17:00.
The site is called Airborne.cam and can be accessed here.
A website built by the University of Cambridge has been programmed to reveal the risk of coronavirus infection indoors and is used by the university to locate locations and make them minor.
The online tool shows that in a 30-person office, which has 100 square meters, with ceilings three meters high, the risk of a person catching the virus from 9:00 to 17:00 if a person is infected and no one does not wear masks is 6.06% (pictured)
The graph it creates that shows a person’s risk of infection is calculated using a series of scientific equations described in a new study published in the Proceedings of the Royal Society A.
Users can determine the occupancy of the room, the type of mask and the activity level. Mask settings do not include mask, surgical masks, N95 masks or fabric covers.
Activity levels can also change, from sitting / breathing to strenuous exercise.
Ventilation can also be changed, with six options ranging from poorly ventilated to industrial hospital ventilation.
Scholars have also built the size of the room and a period of time that is included in the equation.
As part of their research, the scientists found that two people speak freely in a poorly ventilated space, while not wearing a mask, they have a higher risk of infection than if one of them coughed.
In the same office and with consistent settings, if everyone wears a surgical mask all day and takes an hour-long lunch break, it drops to just 2.13% (pictured)
In the image, the different settings that can be changed by users to calculate a certain level of individual risk for a space through the Airborne.cam website
This, they say, is due to the fact that speech leads to the expiration of small droplets called aerosols that float around a limited space.
Without adequate ventilation, they can remain in the air, increasing the risk of a person inhaling them and then becoming infected.
However, a cough produces large drops, which are much heavier and likely to fall to the nearest surface and not remain suspended in the air.
“Our knowledge of the airborne transmission of SARS-CoV-2 has evolved at an incredible rate, considering that only a year has passed since the virus was identified,” said Dr. Pedro de Oliveira, the first author of the paper.
“There are different ways to approach this issue. In our paper, we consider the wide range of respiratory drops that people exhale to demonstrate different scenarios of airborne viral transmission – the first being the rapid spread of small infectious drops over a few meters in a matter of seconds, which can be it happens both inside and inside. Outdoor.
“Then we show how these small drops can accumulate in long-term indoor spaces and how it can be attenuated with adequate ventilation.”
The free online tool shows that in a 30-person office, which is 100 square meters (1,076 square feet) with three-meter (9.8ft) high ceilings, the risk of a person catching the virus from 9:00 to 17:00 if a person is infected and no one wears masks is 6.06%.
If everyone in the office wears a surgical face mask all day and takes an hour-long lunch break, it drops to just 2.13%.
But if three people work in a medium-sized dining room (18 square meters / 193 square meters) that has poor ventilation and one person is infected, the risk of catching the virus in eight hours is 48.73%.
The calculations are based on the assumption that “hands are washed and that individuals are far from each other – ie there is no risk of transmission over short distances by drops / aerosols”.
The tool is currently being actively used by the University of Cambridge, which has made it a prerequisite for high-risk spaces in the institution, which will allow staff to introduce mitigating factors, such as reduced capacity or increased ventilation.
“The tool can help people use fluid mechanics to make better choices and adapt their daily activities and surroundings to suppress risk, both for themselves and for others,” said co-author Savvas Gkantonas, who led the development. of the application with Dr. de Oliveira.
A similar tool was previously created by researchers across the Atlantic at MIT.
The tool reveals that the size or type of room doesn’t matter so much – but what types of masks people wear, and the ventilation system it is equipped with can dramatically lead to up or down risks.
In a standard room with 8 ft high ceilings and each wall about 15 ft long, 10 matching young people who diligently wore surgical masks could sit safely talking for two hours if the windows were closed due to 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 those raised. voices – the instrument shows that the safety limit is reduced to only three minutes.
Its developers say that the online site allows people to calculate risk with more nuances than simple and often vague guidance to form “bubbles” or social distance.
The calculations informing the site were published by authors John Bush and Martin Bazant on the print server on medRxiv.
MIT tool settings for homes, schools, and restaurants suggest that a few people in any of them are probably safe for days in a home with more space or hours in the restaurant – but once the rooms are occupied more densely, the risk increases