The researchers’ work clearly shows public restrooms can be dangerous places for potentially becoming infected from a virus, especially during the COVID-19 pandemic. Other work has shown that both feces- and urine-based virus transmission is possible. Flushing a urinal, much like flushing a toilet, involves an interaction between gas and liquid interfaces. The result of the flushing causes a large spread of aerosol particles to be released from the urinal, which the researchers simulated and tracked. The trajectory of the tiny particles ejected by flushing a urinal “manifests an external spread type, with more than 57% of the particles traveling away from the urinal. When men use urinals within a public restroom, these tiny particles can reach their thigh within 5.5 seconds when compared to the toilet flush, which takes 35 seconds to reach slightly higher.
— source American Institute of Physics | Aug 18, 2020