Brass players most likely to spread COVID-19 with their instruments
In recent years, musicians and scientists have become aware of the risk of spreading COVID-19 during orchestra rehearsals. Even the Vienna Philharmonic Orchestra conducted a study to investigate the risk their instruments posed to people sitting nearby. Now, a recently published study by researchers at Colorado State University further confirms that wind instruments, especially those in the brass family, are most likely to spread respiratory particles.
Aerosol expert and professor of mechanical engineering John Volckens and his CSU colleagues worked with 81 volunteer musicians to measure how different wind instruments spread respiratory particles and what measures could be used to reduce the risk. Using an aerosol measuring chamber, they detected aerosols of different sizes and examined how much each instrument produced. Notably, some implements were larger spreaders than others. On average, brass instruments such as tuba, trumpet and trombone release nearly three times more aerosols than woodwind instruments such as oboes, clarinets or bassoons.
To put this into a bit of context, the vocals were in the same ballpark as the brass and there were reported outbreaks of COVID-19 spread during choir rehearsals.
One way to reduce the risk associated with trumpets, tubas and trombones is to use bell covers, which capture particles from the end of the instruments. However, in a statement to CSU, Volckens warns that’s probably not enough. “The data suggests that masks and bells reduce particles leaving the mouth or instrument by half to 75%. And the reason blue surgical masks or bell covers don’t work better is that they just don’t fit well. These devices do not reach the N95 protection level. Also, the bell covers didn’t seem to have much effect for oboes and clarinets, and there wasn’t enough data to determine if they worked for several other instruments.
Knowing what we now know about how COVID-19 spreads through the air and the amount of brass and woodwind instruments that can contribute to it, Volckens also pointed out that the closure of concert halls and spaces rehearsal early in the pandemic likely saved lives. “I really want to honor them by acknowledging that decision and the economic and mental hardship that followed,” Volckens said. “Thank you for making a very hard sacrifice on our behalf.”
For now, many orchestras and bands have resumed regular rehearsals, with varying levels of safety precautions. But understanding exactly which instruments are the biggest aerosol dispensers will come in handy for any future respiratory infectious disease outbreak (or the next big wave of COVID-19, because that hasn’t gone away yet!)