COVID-19 can be transmitted directly, via large droplet spray, and indirectly, via infected surfaces. It is likely that transmission can also occur via aerosols. These small saliva droplets and their residues can remain suspended in the air for a long time and travel much farther than 1.5 m. This implies that COVID-19 transmission via aerosols could be possible for sporters and spectators in a stadium or an indoor sports hall.
The measurements in the Johan Cruijff ArenA will first be performed without audience, using artificial aerosol generators on the stands. These generators will disperse aerosol amounts similar to enthusiastic football supporters. Between the generators, 184 aerosol particle sensors are mounted to provide insight into the spreading of the small saliva aerosols.
Finally, large-scale air cleaning systems will be employed to analyze to what extent the aerosols can be removed from the stadium air with systems that combine cold plasma, glass fiber, electrostatic precipitation and active carbon and that are placed next to the seat rows. Dependent on permission by the Dutch authorities, TU/e, Johan Cruijff ArenA, Plasmamade and Ajax also want to test with a real-life audience of spectators. They hope these tests can be performed in January. The research in the ArenA stadion is led by TU/e professor Bert Blocken of the department of the Built Environment, an expert in the field of air flows.
The researchers also focus on the viability and survivability of the virus in aerosols, the infection risk, the transmission by large droplet spray versus aerosol inhalation, the aerosol concentration build-up and removal in sports accommodations and the movement of large spectator masses inside and around the accommodations.
In addition, a general risk analysis methodology will be developed that can help the sports organizations and government authorities to further finetune their guidelines and protocols. First results are expected early 2021.
The research project is performed in collaboration with Leiden University Medical Center, Utrecht University, the Johannes Kepler University in Linz, PlasmaMade, GO2Sure and the test venues Johan Cruijff ArenA, Maaspoort Sports and Events via Heroes Den Bosch and the top sports centers CTO Papendal and CTO The Hague.
The collaboration project is co-funded by the PPP Allowance made available by Health~Holland, Top Sector Life Sciences & Health, to stimulate public-private partnerships. The project is also enabled by Sportinnovator.