(1/n) 10 days into our 6-mo study of the aerosol generation from musicians and performers and we have completed some exploratory experiments. Refining our approach continues and includes flow visualization, aerosol measurements in a test chamber and CFD modeling.

(2/n) Project team: me (PI), Dr. Hertzberg, @marinavance, Dr. Toohey, Dr. Patel, Mr. Kumar and Ms. Stockman ( @CUEngineering); Dr. Srebric, Dr. Zhu and @Don_Milton (Univ of MD)

(3/n) Because the results are VERY exploratory at this time we preliminarily conclude:
Instruments generate aerosol in the ranges of sizes that can stay airborne for long periods of time indoors and are in the range of concern that can contain virus (0.2 - 10 microns).

(4/n) Different instruments generate aerosols quite differently (flute, clarinet, trumpet, french horn, trombone, singing so far).

(5/n) Mitigation measures that appear effective at reducing aerosol release are playing with masks (with slits for instrument) and bell covers (multiple layer nylon). General room air cleaning with a HEPA air purifier is also effective.

(6/n) Additional interesting scientific observation is the large numbers of ultrafine particles (< 0.1 microns) that are generated while playing brass and woodwind instruments, but are too small to contain the SARS-CoV-2 virus.

(7/n) preliminary CFD results confirm that the 2-2.5m distance is important to maintain between singers, and that indoor rehearsals should be kept to less than 30 min to reduce risk in a 3 ACH room.

(8/n) Preliminary results are shared in the interest of providing some guidance for musicians to consider how to reduce risk. Data will be processed in detail, quality assured, analyzed and published using our standard scientific approach and thus will take some time...