In the past few years there have been several studies that measure how wind instruments spread aerosols. The information has been used to create guidelines for orchestra and band rehearsals, where musicians often sit or stand very close to each other for several hours at a time. One of the consistent findings has been that musicians playing wind instruments spread more aerosols than others, but a new study now suggests that they are not quite at the level of the aerosols spread by singing or loud speaking.
A new study looked in detail at how wind instruments spread aerosols and found that it could be less … [+]
In a new research article published in the Journal of Aerosol Science, researchers from the groups of Eberhard Bodenschatz and Mohsen Bagheri at the Max Planck Institute for Dynamics and Self-Organization (MPIDS) in Germany describe how they tried to address some of the inconsistencies they noticed in previous studies of aerosols and wind instruments. For example, one of their concerns was that most of the existing research studies all used the same aerosol detection machine and that this particular machine doesn’t detect aerosols below a certain size. Another thing they noticed was that the particles emitted from wind instruments vary in size based on the humidity and temperature of the room the musicians were in, so they needed to make sure that these factors were all kept consistent.
Bodenschatz and Bagheri set up a new study that looked at twenty different types of music instruments, played in a room under tightly controlled conditions. They measured different sizes of aerosols and also took into account what the risk would be depending on whether the musician was using a bell cover to limit aerosols and if the audience in the room was wearing a face mask. The calculations went into a lot of detail to take all these factors into account and ultimately the researchers learned a few new things that could be interesting to note for anyone involved in music groups.
“Surprisingly, we found that musical instruments are less risky than talking or singing,” said Bagheri in a statement to MPIDS. Even though they still spread aerosols much more than regular breathing does, many of the larger respiratory droplets appear to be trapped by the instruments themselves and don’t spread very far. But smaller aerosols do make it out and are mixed in with the other air in the room. That’s why it’s important to make sure that spaces where musicians play are well-ventilated.
The researchers also looked at the effect of wearing masks or bell covers, and as expected found that those were able to reduce the spread of aerosols. If both the instrument and audience were protected by adequate bell covers and masks, the risk of transmission could go down to 0.2% (1 in 500).
“With adequate ventilation and the wearing of FFP2 masks, lessons, rehearsals and concerts with wind instruments can be conducted safely,” Bodenschatz told MPIDS.
That’s good to know, especially now that in several countries a new wave of COVID-19 infections coincides with the fall semester for school bands and orchestras.
