Throughout the COVID-19 pandemic it became clear that airborne transmission of infectious respiratory particles plays an important role in how the virus spreads. The performing arts, from Broadway to the Colorado State University Center for the Arts, took a brutal hit early on, as singing, speaking, and playing instruments in crowded venues were suspected of putting both performers and performers alike. audience members at high risk of exposure. .
Those suspicions were confirmed in a CSU study that measured respiratory particles produced by people who sang or played instruments. Is singing worse than talking when it comes to how many particles are emitted? Yes, according to the study. And the louder you speak or sing, the worse the emissions. A person’s age and whether they are male or female also affects their respiratory emissions, as men and adults emit more particles into the air, on average, than women and minors.
The study was called Reducing Bioaerosol Emission and Exposure in the Performing Arts: A Scientific Roadmap for a Safe Return of COVID-19. Released early in the pandemic before vaccines became widely available, it was led by John Volckens, a professor in the Department of Mechanical Engineering with appointments at the CSU Institute of Energy, the Colorado School of Public Health, the School of Biomedical Engineering and the Department of Radiological and Environmental Health Sciences. His team partnered with Dan Goble, director of CSU’s School of Music, Theater and Dance, to determine the extent to which singers, musicians, and actors emit aerosols (tiny airborne particles less than 100 microns in size), and whether those emissions could be quantified.
The collaboration’s first peer-reviewed article, published this week in Environmental science and technology charts Through open access, it confirmed what engineers had suspected about airborne particulate emissions that pertain to certain activities. Singing produced 77% more aerosols than talking; adults produced 62% more aerosols than minors; and men produced 34% more aerosols than women. The recent article only contains results of the study’s singing and conversation experiments; The results of the use of wind instruments are pending further data analysis and peer review.
Goble and his colleagues raised nearly $ 100,000 in support of the study, including gifts from the United States Institute of Theater Technology, Conn-Selmer, and Yamaha Corp.
The core technology of the study was an aerosol test chamber in the laboratory at the Powerhouse Energy Campus in Volckens, of which only a few exist in the U.S. Approximately 100 volunteers between the ages of 12 and 61 sat or they stood in the chamber and sang, spoke, or played instruments while sophisticated equipment captured and measured the respiratory particles they were producing. They took measurements while the subjects were masked and unmasked.
Among their key findings, that while there were differences between the amount of particles emitted by minors (children 12 to 18 years old) versus adults, or men versus women, those differences were largely due to the volume of participants’ voices and fully exhaled carbon dioxide. . In other words, a man could produce more particles speaking normally compared to a 12-year-old; but the child who sings or shouts can produce more or as many as the man.
These observations were important, Volckens said, because they lend credence to the idea of measuring carbon dioxide levels and noise levels in an enclosed space as a means of measuring transmission risk.
“If there were significant differences after accounting for the CO2 between men, women and children, then you would have to know how many men, women and children were in a room to estimate the risks of transmission, “said Volckens.” Our data suggests that you don’t need to know that if you only measure CO.2 and noise levels, because those measures compensate for these demographic differences. “
CO2 and noise level monitoring together, say at an indoor performance venue, could act as a simple, low-cost risk indicator of airborne disease transmission, and not just COVID, but any airborne disease. air like the seasonal flu or the common cold, Volckens said.
How the results have been implemented
Goble said working with CSU engineers helped his team better understand how visual and performing arts could re-implement their programming after being fully closed or virtual for many months. Goble and his colleagues presented physical distancing, room occupancy limits, room ventilation, and masking protocols to the Pandemic Preparedness Team in fall 2020. He and Volckens gave webinars that provide preliminary information from the study to groups like the Association. National Music Schools who were eager to learn what CSU researchers were discovering.
“We wanted to release some of that information as soon as possible so that people could make informed decisions based on their situations,” Goble said.
At CSU, the performing arts look a little different, but are largely back on track after going fully virtual in the spring of 2020. Their current protocols include things like extra time between classes for performance venues to experiment. Sufficient air exchanges between rehearsals, physical distance of at least 6 feet for voice lessons, and restrictions on the times of occupation of the places. The use of masks, the wide availability of vaccines and CSU’s 90% vaccination rate have changed the game for the performing arts, Goble said, allowing program leaders to implement layered risk mitigation while allowing rehearsals, presentations and lessons.
“We are very fortunate to have experts like (Volckens) who gave us really wonderful information to help us make decisions about what we can and cannot do at the (University Center for the Arts),” Goble said.