The back corner of a classroom has long been the domain of mischievous children, but it may also be the safest spot in the room to avoid catching the coronavirus, a US study claims.
Schools have been hit hard by the pandemic, with many forced to close, cancel exams and overhaul their teaching methods.
And much research has looked at how to minimise the risk to both staff and pupils, with open windows and air conditioning hailed as effective solutions.
New research backs this up, but also reveals that in a typical classroom the lowest concentration of coronavirus particles is often in the back corners.
The back corner of a classroom has long been the domain of mischievous children, but it may also be the safest spot in the room to avoid catching the coronavirus, a US study claims (file photo)
Researchers from the University of New Mexico say this information could allow for high-risk students to be placed in the low exposure zones.
In the study, published today in the journal Physics of Fluids, the scientists used a computer model to see how open windows, perspex screens on each desk and air conditioning impacts the spread of aerosols and droplets.
Khaled Talaat, co-author of the study, told MailOnline that the specific location of a room’s safe zones are dependent on its specific layout and ventilation.
But the researchers used industry-standard air conditioning systems and rooms of ‘realistic dimensions and size’, to make the findings as wide-reaching as possible.
Researchers from the University of New Mexico say the low concentration zones and back corners could be used to keep high-risk students away from the most danger (file photo)
‘Classrooms do exhibit some variability which can affect the quantitative findings but the overall qualitative findings should hold [true for most classrooms],’ Mr Talaat, a PhD candidate, explains.
The researchers looked at how aerosol particles spread through the air in a classroom following expulsion via talking, coughing, laughing or sneezing.
‘Nearly 70 per cent of exhaled particles smaller than one micrometre in size exit the system when windows are open,’ Mr Talaat says.
‘And air conditioning removes up to 50 per cent of particles released during exhalation and talking, but the rest get deposited onto surfaces within the room and may reenter the air.’
However, while these tried and tested methods were again found to be worth employing, the team also found screens in front of desks were effective.
‘Screens don’t stop 1-micron particles directly, but they affect the local air flow field near the source, which changes the particle trajectories,’ Mr Talaat adds.
‘Their effectiveness depends on the position of the source with respect to the air conditioning diffusers.’
Face masks make the cloud of coronavirus particles created by a cough up to 23 TIMES smaller
Wearing a face mask reduces the size of the clouds of infectious coronavirus particles created by a cough by up to 23 times, a study has found.
Researchers from India calculated how cough clouds evolve as they spread out — and how much various forms of covering can control their spread.
The team found that a surgical facemask lowered the cloud volume by seven times compared with without — while an N95 respirator cut the volume 23-fold.
‘We found that anything that reduces the distance travelled by the cloud… should greatly reduce the region over which the droplets disperse upon coughing,’ said paper author and engineer Rajneesh Bhardwaj of the Indian Institute of Technology.
This, he added, in turn therefore greatly reduces ‘the chances of infection.’
Researchers found a surgical facemask lowered the cloud volume by seven times (green line) compared with no mask (red line)— while an N95 respirator cut the volume 23-fold (blue line)
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