Risk of Sports-associated Long-range Airborne Transmission of SARS-CoV-2: A Mathematical Modeling Study

The worldwide pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants remains a health threat. As sports event-related outbreaks due to long-range airborne transmission in ventilation have been reported, the present study aimed to quantify infection risk using available data and apply the results to an outbreak in an ice hockey arena.

A mathematical modeling approach was used to estimate the risk of airborne infection.

A quantum was defined as the dose of airborne droplet nuclei required to cause infection in 63% of susceptible persons. The estimated quanta emission rate per infector showed a log-normal distribution with a geometric mean (GM) of 28.81, geometric deviation (GD) of 5.78, and median of 22.65 quanta/h. The estimated average time-average quanta concentration (C; quanta/m³) showed a log-normal distribution with a GM of 0.08, GD of 5.80, and median of 0.06. The outdoor ventilation rate per infected person for the scenario showed a log-normal distribution with a GM of 710.96, GD of 6.22, and median of 169.17 m³/h. A higher C value indicated exposure to SARS-CoV-2 due to the lower ventilation rate in the a rena a nd the large expiratory volume of athletes caused by intensive exercise.