NEW scientific evidence from Germany has cast doubt on the claim that singing constitutes a high-risk activity in the transmission of Covid-19.
This and other evidence suggests that, with adequate risk assessment and social distancing, singing could be restored in some contexts as part of church life in the UK.
Stories about the danger of transmitting the coronavirus through singing have proliferated since the widely reported outbreak of Covid-19 in Washington State, where 53 of the 61 members of the Skagit Valley Chorale fell ill after rehearsals on 3 and 10 March, immediately before lockdown measures. The incident was subsequently correlated with two other “super-spreader” events involving choirs in Amsterdam and Berlin (News, 29 May).
An investigation by the US Center for Disease Control and Prevention, however, established that Skagit Valley choir members were sitting six to ten inches from one another, and sharing snacks and stacking chairs together, and that 19 members with “probable symptoms” were never tested.
A statement that “emission of aerosols” was related to “loudness of vocalisation” was a footnote to one of its studies, which fed into an existing debate about whether the virus was transmissible through small, light aerosol particles as well as the heavier and larger droplets.
A professional musician, Ed Ballard, has studied this incident and the most commonly available scientific material online. Institutions needed this sort of information to manage the risk in their own circumstances, he suggested. He was keen that the evidence that existed speak for itself. He quoted the World Health Organization (WHO) and Public Health England on aerosol transmission, and had links to some of the most-quoted scientific studies.
Although some are based on expert opinion, only one was based on Covid research. The starting assumption of most contradicted the WHO’s position that aerosol transmission was not an accepted transmission pathway of the coronavirus. Others look at amplitude of speech, a different physiological mechanism, rather than singing.
The risk from droplet particles — rather than aerosol particles — remained a pressing concern, Mr Ballard said. The one study based on research specifically into the safety of singing in the context of Covid has come from the Institute of Fluid Mechanics and Aerodynamics in Munich: “Singing in choirs and making music with wind instruments — Is that safe during the SARS-CoV-2 pandemic?”
In the study, detailed measurement of the ballistic propagation of larger droplets when singing and speaking, and the flow-related spreading of small droplets, was conducted with a professional singer and vocal coach at the Mozarteum in Salzburg, and two amateur choral singers and five professional musicians.
The Munic study concludes: “Air is only set in motion in the immediate vicinity of the mouth when singing. In the case of the professional singer, the experiments showed that at a distance of around 0.5 m, almost no air movement can be detected, regardless of how loud the sound was and what pitch was sung. It is therefore unlikely that the virus could spread beyond this limit via the air flow created during singing.”
The researchers deemed this to be “not surprising, since singing does not expel a large volume of air in jerks like coughing or sneezing”. They concluded, with provisos: “If the findings and recommendations from our quantitative measurements are taken into account, then making music in a community should be relatively safe.”
Similar experiments have been carried out for orchestral instruments, in research commissioned by the Bamberg Symphony Orchestra and the Vienna Philharmonic. The Freiburger Institüt fur Musikermedizin, which previously deemed singing a danger, has now released new guidelines that “Two metres will result in there being no increased risk of infection through droplets.”
They also conclude: “Singing in very large enclosed spaces such as concert halls and church spaces appears to be very favourable.”
In their guidelines, “A Risk Assessment of a Coronavirus Infection in the Field of Music”, the authors advise: “Every institution develops its own risk management according to its own musical settings. It is to be expected that the greater the number of risk mitigation measures in place, the stronger the decrease in the risk of infection. This process should be accompanied by advice from company physicians, health officials, etc.”
In continental Europe, there has been a more concerted approach to establishing the risks associated with singing, and deciding a framework in which they can be managed safely. Mr Ballard, who emphasised that he was not a scientist, hoped that the material that he had collected “brings together the right questions, and moves us on from examples that have not been helpful.
“There’s no question that, for the foreseeable future, we are going to have to do things differently,” he said on Tuesday. “But that’s a very different proposition from singing itself occupying some unique status as a dangerous activity.”
Read an article by Ed Ballard on the research here