The COVID-19 pandemic has brought global sports to a halt and led to uncertainty of how leagues will complete the season in progress. While North American leagues like the MLB, NBA, and NHL have just started up again, time will tell how successful their COVID control plans are.

Nonetheless, soccer has resumed across Europe and a recent preprint by scientists at The Hebrew University of Jerusalem highlights how this restart can be made safer by simply scheduling matches strategically. 

The, researchers focused on the primary surfaces most contacted by soccer players. They began by taking grass and synthetic leather (as a proxy for the ball’s surface) and monitoring how long a virus very similar to SARS-CoV-2 survived on them at two time points when matches are frequently played: mid-day (1:00 PM, ~30 degrees Celsius) or nighttime (8:00 PM, ~22 degrees C). 

They saw a stark difference in virus survival. Surfaces exposed to mid-day conditions had little virus survival past 90 minutes, while nighttime exposed surfaces remained contaminated for 24 hours. They pointed to differences in heat and UV light as the potential mediators of virus inactivation. These findings suggest that organizers of European soccer leagues should schedule matches at mid-day for safety.