Reprint
of .pdf text from Covid 19 aerosol and breath experiments
Orchestra, brass, woodwind, musical instruments researched from
various studies
Originally presented May, 2020 (with links)
Printed here for education and convenience are recent studies
and links regarding breath, aerosol measurements, and Covid 19
safety for orchestra and band musicians, as well as charted
distances. The study is from University of Southern Denmark.
HERE IS THE LINK TO THE ORIGINAL DOCUMENT (and more visuals) TO
DOWNLOAD.
http://www.encroach.net/measurement_of_aerosol_from_brass_and_woodwind_instruments.pdf
Also, University of Colorado is currently doing experiments and some
information has been leaked out.
Initial research indicates a simple cloth over the instrument bell
will provide 50% aerosol reduction (already minimal).
I will update this site when more research becomes known.
TEXT ONLY FROM THE original .PDF (go to link for charts)
"Lars Brandt MD PhD, Department Chairman, Ass. Professor
Center for Performing Arts Medicine
Department of Occupational and Environmental Health
Odense University Hospital
Department of Clinical Research
University of Southern Denmark
Background
During spring 2020 the COVID 19 pandemic has swept across the world
leading to the lockdown of many activities among those cultural
activities like music performance. However, in many countries the
COVID 19 is now under control and gradually reopening has started
with hygienic precautions.
During the last decades studies have been performed to understand
the mechanism of contact and airborne spread of infectious agents,
such as viruses causing respiratory syndrome epidemics. It is well
established that droplets and aerosols transported by expired air
result in short range airborne transmission of virus. Sneezing and
coughing produces high speed airflow with high concentration of
droplets and aerosols expelled up to 1.8 meter. Furthermore it has
been shown that virus to some extent is spread with very fine
aerosols throughout a room depending on room ventilation.
Questions have been asked whether different cultural performances
are safe with respect to spread of COVID 19 infection. There is for
instance concern about the spread of aerosol while playing brass and
woodwind instruments. The immediate thought is that blowing in the
instrument may produce airflow containing aerosols, which could
contain COVID 19 virus if the musician is infected. It has been
suggested that safe distance playing brass and woodwind instruments
has to be 3 to 4 meters. However, this is not based on solid
knowledge about airflow from the bell of the instruments. Keeping a
distance of 3-4 meters will entail great challenges concerning room
size for rehearsals or concerts and for the artistic expression.
However, there has been no substantial documentation based on
measurements for this recommendation. But during the last months
several experiments to measure airflow and spread of aerosols
playing brass and woodwind instruments have been performed.
Preliminary results from The Bamberg Symphony investigating airflow
from bassoon, trombone, clarinet oboe and horn revealed hardly any
measurable air movements while playing the instruments.
https://www.br.de/nachrichten/bayern/bamberger-symphoniker-wissenschaftler-messen-
aerosolausstoss,Ry6T6OU?fbclid=IwAR0q9LfNqv3QFBZ6EiWDlKs2vvNEnBJKb96oYhDa-PeKx6ePGu9jQqy5RrQ
In another study occupational hygienist Thomas Eiche measured
expelled droplets and aerosols while playing brass and woodwind
instrument, measuring aerosols (<= 5μm) and droplets (> 5μm)
concentrations at 1.2-1.6 nl/m3 and 0.1-0.8 nl/m3 respectively,
highest for clarinet.
https://www.thomaseiche.ch/
https://www.svtb-astt.ch/wp-content/uploads/2020/05/200522-Schutzkonzept_COVID-
19_Theater_Konzert_Veranstaltung_V2_2.pdf
Another experiment, commissioned by the Vienna Philharmonic,
examined the movement of musicians' breath while performing. The
study involved members of the orchestra each being fitted with an
aerosol device inside their noses, which spayed a fine mist into
their lungs. They were then placed in front of a black canvas and
very brightly lit from the front, then photographed while playing.
This made it possible to view the mist and the extent to which it
travelled in the air.
The results showed that for string players the maximum distance the
droplets travelled was around 0.5 m while playing and being at rest.
For brass and woodwind instruments, no significant amount of mist
cold be detected around the area of the instruments’ openings. The
only exception to this was the flute, where droplets were observed
up to 0.8 m
from the musician. Clouds of air were observed in the area of the
mouth, regardless of the breathing
https://wien.orf.at/stories/3049099
The Institute of Aerodynamics of the University of the Bundeswehr in
Munich conducted flow experiments with 8 brass and woodwind
musicians using Particle Image Velocimetry to measure air velocity
and the movements of droplets emerging form the instruments. They
observed airflow at 0.5 m from the bell of brass instruments. The
larger the brass instrument had the lower exit velocity and air
movement. Woodwind caused airflow more than 1 m. As a conclusion
they recommend safety distance to be 1.5 m.
https://www.unibw.de/lrt7/video-musizieren-waehrend-der-pandemie-was-raet-die-wissenschaft
https://www.youtube.com/watch?v=BYo3wlWUDDM
Measurement aerosols from brass and woodwind instruments, Odense
Symphony Orchestra
The Musician Health Clinic, Department of Occupational and
Environmental Health, Odense University Hospital together with
Odense Symphony Orchestra performed an experimental study on 7th,
14th and 15th May 2020 measuring airborne particles from brass and
woodwind instrument, playing at distances of 0.5,1,2,3 and 4 meters.
The measurements were performed in rehearsal room 1.
TSI Dust Trak tm aerosol monitor was used to measure airborne
particle concentration by measuring total particle mass in mg per
m3, and for particle mass under 1, 2.5, and 10 μm.
The aerosol monitor was placed on a music rest, and the distances
were marked on the floor with tape. The musicians played one to two
minute standing 0.5, 1, 2, 3 and 4 meters from the aerosol monitor.
Background particle concentration in the room without any activity
was measured at the start. The musicians were asked to perform a
music piece and play with the same effort as under a concert. The
instruments were tuba, clarinet, trombone, fagot, oboe, trumpet,
horn and flute.
Results
The background mass of particles were 0.004, 0.005 and 0.006 mg/m3
for particles less than 1, 2.5 and 10μm respectively, and the total
mass of particles was 9 mg/m . As seen in table 1, measured particle
mass was quite similar for tuba, clarinet and trombone compared to
the background measure, and a little higher for fagot, trumpet,
oboe, horn and flute. In contrast, coughing at a distance of 0.5 m
produced 70,000 times higher levels of particles.
The measurements showed based on visual examination that there was
no significant variation in the aerosol concentration while playing
0.5 m from the monitor or standing at a distance of 1, 2, 3 or 4 m,
as seen in figure 1-8. During the time period noted on the x-axis
the musician stepped progressively backward away from the monitor.
The y-axis shows the size range of particles/aerosols measured. The
may differ for the each instrument. The x-axis shows the time period
when measurements are taken. The small fluctuation in the aerosol
concentration corresponded to the small fluctuation in the
background measurements (Figure 9). There are some small peaks,
which not can be explained by distance from the monitor or by
variation in the playing the music. The most likely explanation is
dust caused by person movement in the room.
Conclusion
The emission of aerosol measured from brass and wood wind
instruments was very low, and almost at the same level as background
concentrations. Other experiments have shown very little airflow and
very small aerosol concentrations at short distances from brass and
woodwind instruments. Based on the actual measurements and the other
studies mentioned 1 meter distance playing brass and woodwind
instruments seems to be safe with respect to the risk of spreading
aerosol from the instruments. This assumes that musician blow
towards the back of fellow musicians.
Acknowledgement
A special thanks to the Odense Symphony Orchestra and the musicians
Rune Most (flute), Henrik Skotte (oboe), René Højlund Rasmussen
(clarinet) Morten Østergaard (fagot), Tone Sundgård Anker (horn),
Per Morten Bye (trumpet), Lukas Winther Andersen (trombone) and Carl
Boye Hansen (tuba) for participating in the study."
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