Researchers at Bristol University looked at how infectious coronavirus is in various settings (Picture: Metro.co.uk)
Covid-19 may linger in shower and steam rooms for at least 20 minutes after an infected person has left, a study has found.
Researchers at Bristol University looked at how infectious coronavirus is in various settings, and discovered it thrives in humid or damp environments.
They found virus particles dry out as they leave the moist conditions of the lungs, which quickly reduces how infectious they are.
But the humidity of the conditions it leaves the body in affects how fast they dry out.
In an office-like environment with humidity at around 40%, the virus loses half its infectiousness within 10 seconds.
But at 90% humidity, which is the equivalent of a shower or steam room, half of particles were still infectious after five minutes. And after 20 minutes, 10% of the virus remained infectious.
Experts also found temperature made no difference to infectiousness, despite the theory Covid-19 does not spread so easily in the summer.
The study investigated three different variants of the virus, including the original one and the Alpha strain which sparked last winter’s spike in cases.
They discovered coronavirus thrives in humid or damp environments, such as in shower or steam rooms (Picture: Getty Images)
The study was published on medRxiv, but has not been peer-reviewed so scientists are yet to have a chance to challenge the findings.
Professor Jonathan Reid, the director of Bristol’s Aerosol Research Centre and the study’s lead author, told the Guardian: ‘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].
‘It means that if I’m meeting friends for lunch in a pub today, the primary risk is likely to be me transmitting it to my friends, or my friends transmitting it to me, rather than it being transmitted from someone on the other side of the room.’
Previously checking coronavirus infectiousness was difficult, using imprecise methods like spraying particles into drums. But this wasn’t representative of real-life scenarios like coughing, sneezing or breathing.
But the Bristol University experts used a new apparatus which levitates virus particles between two electric rings for between five seconds and 20 minutes.
The temperature and humidity can then be adjusted to mimic a variety of different environments and situations.
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