New research suggests that singing does not produce substantially more respiratory particles than speaking at a similar volume. But this all depends on how loud a person is, according to the initial findings which are yet to be peer-reviewed.
As the pandemic swept across the world in March, theatre venues across the UK closed their doors, causing a devastating impact on the performing arts sector.
Having been deemed as a higher risk activity for the spread of the virus, live indoor performances were cancelled until last weekend when the government announced that indoor performances could go ahead with strict social distancing. Though few theatres are now beginning to make plans for reopening, the majority still remain closed because it is simply not economically viable for many to open as they need to play to, at least 70 to 80% capacity to break even.
As we move into Stage 5 of the government’s roadmap to recovery (indoor performance with fuller audiences), a new research project has been supported by Public Health England and the Department for Digital, Culture, Media and Sport, and was carried out by a team of researchers including from Imperial College London, the University of Bristol and Royal Brompton Hospital.
The new project, called Perform, looked at the amount of aerosols and droplets generated by performers. The findings could have implications for live indoor performances.
Aerosols are tiny particles which are exhaled from the body and float in the air. There is emerging evidence that coronavirus can be spread through these particles, as well in droplets that fall onto surfaces and are then touched.
Twenty-five professional performers of different genders, ethnicities, ages and backgrounds – musical theatre, opera, gospel, jazz and pop – were invited to take part in the study. They were asked to individually complete a number of exercises including singing and speaking Happy Birthday at different pitches and volumes, in an operating theatre where there were no other aerosols present.
The researchers then analysed the aerosols produced by specific sounds and found that the volume of the voice had the largest impact on the amount of aerosol produced. For example, there was some small difference between speaking and singing at a similar level, however singing or shouting at the loudest level could generate 30 times more aerosol.
Researchers also found that ventilation could have an impact on how aerosol builds up. The larger the venue and the more ventilation there is could affect how concentrated the volumes are.
Jonathan Reid, professor of physical chemistry at the University of Bristol, is one of the authors of the paper, which was supported by Public Health England.
He said: “Our research has provided a rigorous scientific basis for Covid-19 recommendations for arts venues to operate safely, for both the performers and audience, by ensuring that spaces are appropriately ventilated to reduce the risk of airborne transmission.”
Culture Secretary Oliver Dowden said: “I know singing is an important passion and pastime for many people, who I’m sure will join me in welcoming the findings of this important study.
“We have worked closely with medical experts throughout this crisis to develop our understanding of Covid-19, and we have now updated our guidance in light of these findings so people can get back to performing together safely.”
Dr Rupert Beale of the Francis Crick Institute, said: “This important research suggests there is no specific excess risk of transmission due to singing. Loud speech and singing both carry excess risk however. This research supports the possibility of safe performance as long as there’s appropriate social distancing and ventilation.”
Dr Julian Tang, honorary associate professor in respiratory sciences at the University of Leicester, said: “The risk is amplified when a group of singers are singing together, eg singing to an audience, whether in churches or concert halls or theatres. It is a nice study but not exactly representative of the real whole choir dynamic, which really needs further study to truly assess the risk of such large volume synchronised singing vocalisations/exhalations.
“The risks should not be overly underestimated or played down because of this – we don’t want choir members getting infected and potentially dying from Covid-19 whilst doing what they love.”
If you’d like to find out more, the research paper Comparing the respirable aerosol concentrations and particle size distributions generated by singing, speaking and breathing, is available on ChemRxiv.