Measurement and rapid assessment of indoor air quality at mass gathering events to assess ventilation performance and reduce aerosol transmission of SARS-CoV-2

To assess risk factors for COVID-19 transmission and address the closure of mass gathering events since March 2020, UK Government ran Events Research Programme (ERP), following which it reopened live in sports, music, culture July 2021. We report rapid post-occupancy evaluation Indoor Air Quality (IAQ) associated long-range airborne conducted Environmental Study ERP. Ten large venues around were monitored with CO 2 sensors at a high spatial temporal resolution during 90 events. An IAQ Index based on concentration was developed, all spaces classified bands from A to G their average maximum concentrations High monitoring depicted overall state ventilation events, allowed identification issues effectiveness distribution, poor settings may be increased. In numerous settings, found follow patterns relating event management specific occupancy venues. Good observed 90% given occupancies. Practical applications: High-resolution indoor is necessary detect variation air quality The paper summarises guidance buildings defines methodology measurement assessment that can implemented by venue managers. Comparisons measured identified pathogens. Building operators should mindful strategies used relative total different occupant’s activities.