Playing wind instruments spreads more viruses than breathing, but less than talking or singing
A relatively large number of viruses can emerge from the clarinet. It releases significantly more aerosols, which may contain pathogens such as SARS-CoV-2, compared to other instruments such as the flute. However, the risk of transmission from an infected person on a wind instrument is generally much lower than for people who sing or speak, provided they spend the same amount of time in its vicinity. This is the conclusion drawn by a research team from the Max Planck Institute for Dynamics and Self-Organization (MPI-DS) in Göttingen and the University Medical Center Göttingen (UMG) in an extensive study. The researchers determined the emission of particles and the associated maximum risk of transmission when playing many different wind instruments. The results provide clues as to how cultural events can be organized with the lowest possible risk of infection, even during the pandemic.
The most risky instrument is the voice, at least when it comes to spreading viruses such as SARS-CoV-2. Compared to silent breathing, during singing or speaking, infected people release more than 500 times particles into the air, which may contain viruses. When people play music with wind instruments, far fewer aerosols enter the environment than during singing – but still 5 to 50 times more than during breathing, as studied by a team led by Mohsen Bagheri and Eberhard Bodenschatz, director of the MPI-DS and professor at the faculty of physics at the University of Göttingen. Together with colleagues from the Institute of Hospital Hygiene and Infectiology at UMG, the researchers analyzed how many particles of which size are released when 20 different wind instruments are played. They took the measurements under controlled conditions in a clean room and determined the upper limit of transmission risk with the omicron variant of SARS-CoV-2 from the results in each case. The study is freely available.
The risk of transmission depends on the instrument
“Amazingly, we found that musical instruments are less risky than talking or singing,” says Mohsen Bagheri, head of an aerosol research group at MPI-DS. As the study by the Göttingen team shows, it is mainly the large respiratory droplets, which are particularly important for the transmission of viruses, which remain trapped in the wind instruments. The instruments thus act as a filter for larger particles. However, wind music is not safe for musicians and audiences from an infection protection perspective. This is due to the fact that particles with a size of less than five micrometers mainly emerge from the instrument. They stay in the air longer and travel further, so they can reach high concentrations, especially in unventilated rooms. The number of these small particles released by wind music is also highly instrument-dependent: while the team measured a very low concentration of released particles for various flutes, the measurements yielded values for the clarinet almost as high. only for singing.
For example, at a distance of one and a half meters from a clarinet and a trombone, the risk of transmission already reaches 50% after four minutes. However, at the same distance from a flute, this risk of transmission is only reached after three hours. All the values of the other instruments measured were between the two.
Masks for instruments and personal protection
In their study, the team also investigated how effectively the risk of transmission could be reduced by particulate filters with properties similar to the fleece of FFP2 masks. They placed the prototype masks at the ends of the brass; the wind instruments were almost completely enclosed in the filter material. “For brass instruments, an instrument mask reliably reduces the emission of infectious particles,” said study lead author Oliver Schlenczek. If, in addition, the public also wears an FFP2 mask, the risk of transmission is only 0.2%, even after one hour. Simone Scheithauer, director of the Institute of Hospital Hygiene and Infectious Diseases at the UMG, considers these results to be very positive: “On this basis, we can recommend much more targeted protective measures in the future and maintain the musical cultural activities with only minor restrictions even in critical situations,” she says.
“With adequate ventilation and the wearing of FFP2 masks, lessons, rehearsals and concerts with wind instruments can take place safely,” concludes aerosol researcher Eberhard Bodenschatz.