Findings were posted on medRxiv ahead of peer review.
“Overall, the expected additional effect of indoor [mass gathering events] MGEs on burden of infections is low if hygiene concepts are applied and adequate ventilation exists,” the study authors wrote.
The team from Martin Luther University of Halle-Wittenberg tested three hygiene scenarios (no restrictions, moderate restrictions and strong restrictions) and used contact tracing devices to assess spectators’ close contacts. They also studied aerosol distribution and concert-goers’ resulting exposure.
The concert was held on Aug. 22 in the Leipzig Arena with 1,212 participants, short of the researchers’ goal of 4,000. All attendees tested coronavirus negative in the two days leading up to the event.
The simulation scenarios with tighter restrictions (like “checkerboard spaced seating” or seating in pairs spaced 5 feet apart with many more arena entrances) revealed that the concert’s entry process lent the greatest opportunity to come into close contact with others, “without major further increases,” study authors wrote.
Researchers also found that placing jet nozzles near the corners of the arena’s roof to project air downwards “substantially increase[d] the airflow and thus reduce[d] density of aerosols.”
However, shutting off the jets and suctioning air at the roof instead was not as efficient; the first scenario resulted in 10 contacts vs. 108 for the second scenario.
“Poor ventilation systems can lead to a considerably higher rate of aerosol expositions and can thereby result in a high number of infections,” per the study.
Also, a survey given to the participants found that 89% wouldn’t have an issue with wearing N95 masks; “sometimes a little restrictive, but they could get used to it quickly,” authors wrote.
However, some experts question real-life application, per the New York Times, and the researchers forewarned of several limitations, including much unknown about airborne transmission related to coronavirus, among other factors.