Not only does singing increase the risk of spreading SARS-CoV-2 and other airborne viruses, but singing louder makes it even worse. A new paper published in Environmental Science and Technology Letters pinpoints some of the risks of spreading COVID-19 (or other airborne diseases) through singing and speaking.
Mary Hughes, a performer with the NY Metropolitan Opera, was a participant in the CSU aerosol … [+]
Ron Bend/Colorado State University
The article is the first peer-reviewed publication from the Reducing Bioaerosol Emission and Exposures in the Performing Arts: A Scientific Roadmap for a Safe Return from COVID-19 project. This collaboration started in 2020 with a goal of finding a way to make music and theatre-based activities safe again.
Last year, the project already suggested that singing was one of the major contributors to spreading aerosols, but this newly published study looked at a few other factors. One was the volume. Singing loudly spreads more aerosols than singing quietly, because it puts more force into pushing out the air. That means that belting it out at a choir rehearsal makes you more likely to potentially spread particles than quietly singing along.
Besides the volume, age and gender also played a role. Children on average spread fewer aerosols than adults, unless they shouted, so a loud children’s party is still risky! Men produced more airborne particles than women, which has to do with the force used to project air out of the lungs and into the surrounding space.
This kind of information is really useful for performing arts groups, because it helps them plan rehearsals and performances in a safer way. For example, knowing that singing loudly is a bigger risk factor than singing quietly can encourage music directors to ask their choir to keep rehearsals at a lower volume.
One other important factor is air flow. All things being equal, a room with great air flow will see airborne particles moving away very quickly, leaving little chance for SARS-CoV-2 virus or other airborne pathogens to infect others. To get an indication of air flow, you can measure the level of carbon dioxide in a space. When a lot of people are singing, speaking, and breathing in an enclosed space, the CO2 levels will go up, indicating less air flow. But based on the results from this latest study, lead researcher John Volckens, professor in the Department of Mechanical Engineering at Colorado State University, recommends not only tracking the CO2 level but also the noise level in the room.
“If there were significant differences after accounting for CO2 between males and females and kids, then you’d have to know how many males, females, and minors were in a room to estimate transmission risks,” Volckens said in a statement to Colorado State University. But that is difficult to keep track of. Measuring noise levels is much simpler, and according to Volckens it’s a good estimate of the actual risk posed by these different groups. “Our data suggest that you don’t need to know that if you just measure CO2 and noise levels, because those measures are an equalizer for these demographic differences.”
So it’s not just about keeping the room well-ventilated, but even keeping the volume lower can reduce the risk of spreading COVID-19 among a choir, theatre group or any gathering where people tend to project their voice. A good reason to tell people to keep it down!
Source by www.forbes.com