The team said they were not critical of the initial investigation, but said the incident continued to be used as the reason for indoor restrictions, even when new evidence emerged questioning the spread in the air in well-ventilated buildings.
The University of Bristol has shown that airborne coronavirus infectivity can decrease by 90% within 20 minutes of exhalation. The same university also found that singing does not produce significantly more respiratory particles than speaking at a similar volume.
Professor Dingwall added: “Even in human challenge trials, where people have had the virus pushed up their noses, only around half are infected.
“There is very strong evidence that humans don’t like to come within a meter of each other if they can avoid it and under normal circumstances our breath travels no more than half a meter. -metre.
“More generally, the stuff you exhale will travel about 20cm and tend to disperse upwards because it’s warmer than the surrounding air.”
Britain banned indoor singing in March 2020 and it took 18 months before the ban was finally relaxed.
“Some are still afraid”
The new findings, published in the journal Public Health, concluded: “The Skagit County Choir outbreak does not provide authority for measures to restrict singing or to require face coverings or physical distancing at indoor gatherings. interior at a relatively low density without special ventilation measures. ”
The research was hailed by Gareth Malone, the choirmaster and TV presenter.
“The outbreak in the Skagit Valley Chorale has sent shockwaves through the singing world, and I’m sure singers everywhere will appreciate having this reviewed again,” he said.
“Singing with others is so good for us in so many ways, but some people are still afraid to sing because of Covid, and so it’s important that we constantly reassess the evidence.”
The researchers said they hoped the document would also exonerate the choir member who spent more than two years believing he was responsible for the infection of dozens of people and two deaths.
They said it was unethical for public health authorities to blame single sources for large outbreaks.