By Charlotte Webster-
Coronavirus loses its ability to infect people within 20 minutes of the virus becoming airborne, according to research
The world’s first simulations of how coronavirus survives in exhaled breath have shown that most of the loss happens within the first five minutes of droplets being sent into the air. Physical distancing and mask wearing is said to be the most effective way of preventing infection, researchers said.
Researchers from the University of Bristol developed equipment that allowed them to generate minute particles containing the virus, gently levitating them between two electric rings for durations of between five seconds and 20 minutes.
Researchers said the speed at which the particles dry out varies according to the relative humidity of the surrounding air, with the virus losing around half of its infectivity within five seconds when it is lower than 50%, after which the decline was slower and more steady, with a further 19% loss over the next five minutes.
Three variants, including Alpha, have been tested by the team, with experiments with the Omicron variant due to start soon, The Guardian reports.
How rapidly particles dry out varies according to the relative humidity of the surrounding air. At levels lower than 50 per cent, the virus lost around half of its infectivity within five seconds, with another 19 per cent lost over the next five minutes
Prof Jonathan Reid, director of the University of Bristol’s Aerosol Research Centre and the study’s lead author, said: “This is the first time anyone has been able to actually simulate what happens to the aerosol during the exhalation process.”
He added: “People have been focused on poorly ventilated spaces and thinking about airborne transmission over metres or across a room. I’m not saying that doesn’t happen, but I think still the greatest risk of exposure is when you’re close to someone.
“When you move further away, not only is the aerosol diluted down, there’s also less infectious virus because the virus has lost infectivity [as a result of time].”