 This research shows that air travel can be a significant source of transmission of SARS-CoV-2, even when travel restrictions are in place. The use of wastewater-based epidemiology, WBE, has been shown to be effective in detecting SARS-CoV-2 in airport sewer systems, suggesting that it could be used as a valuable tool in monitoring the global spread of the virus. This article was authored by Cata Farkas, Rachel Williams, Natasha Alexander's, and others.