TORONTO — As concerts and live theatre begin to return, a new study says that safety measures such as time limits, social distancing and putting a mask over wind instruments can go a long way in reducing airborne transmission of COVID-19 during performances.
The study was published on Friday in the journal ACS Environmental Au and led by researchers from the University of Colorado Boulder and University of Maryland. The authors investigated the flow of aerosols during musical and theatre performances.
Aerosols are microscopic airborne particles that are expelled while talking, coughing, sneezing, singing or playing wind instruments, and could carry the SARS-CoV-2 virus.
“COVID has shown people that aerosol transmission of respiratory diseases is something that happens. But just because it goes into the air doesn’t mean that everyone is going to contract this disease,” said lead study author Tehya Stockman in a news release.
“We found that there are ways to mitigate these aerosols in a space and ways to reduce your risk.”
While earlier studies have looked at the spread of COVID-19 through singing, there hadn’t been any research done on how the virus could spread through musical instruments. Stockman and her colleagues first embarked on the study last fall to fill in this research gap.
Masks were one of several measures that were found to be effective at reducing the presence of aerosols, even for wind instruments.
Researchers found that covering the bell of a clarinet with a surgical mask or fitting a MERV13 filter material over the bell of a brass instrument was effective at reducing the amount of aerosol particles from the instrument as well as reducing the speed at which the particles were expelled.
Playing a wind instrument without any protection led to an average peak aerosol content of 1.0 particles per cubic centimetre. But with a bell mask, aerosol content dropped to just 0.36 per cubic centimetre.
For woodwind instruments, such as clarinets, some air was able to escape through the keyholes. However, the researchers say that amount of air that was able to escape was minimal and did not significantly increase the risk.
Distance matters as well, researchers say. Individuals who are located the closest to performers have the highest risk of transmission. But performance time was found to be an even more significant factor.
Researchers say instrumental performances should be limited to 30 minutes indoors or 60 minutes outdoors. Performances that were longer were found to be a significant risk of transmission (greater than 10 per cent risk), even for people located further than six feet away from the performer.
While researchers say no known COVID-19 outbreaks have been linked to woodwind instruments, there was a notable outbreak in back in March 2020 where 52 people in Washington state tested positive for COVID-19 after a choir practice.
Stockman, who herself is a clarinet player, hopes that the study can offer a way for musicians to keep concerts open and safe.
“What we’ve shown is that there’s easy measures to take that make life still be relatively normal—and you don’t have to fear the air,” said Stockman.