Flushing a toilet creates a “toilet plume” that can stick around in the air well after the flusher leaves and could contain particles of the coronavirus, according to researchers.
Researchers at Yangzhou University found the particles remain airborne long enough that the next person to use the bathroom could inhale them, according to the study in the journal Physics of Fluids. Researchers used computer simulations to trace where particles could travel once a toilet is flushed.
The study found that between 40% and 60% of particles may rise above the toilet seat, spraying over three feet into the air.
It’s not clear if people can contract the coronavirus this way, though another study found the virus in patients’ fecal matter. There are no confirmed cases of the virus spreading from feces to a person, according to the Centers for Disease Control and Prevention.
“Scientists also do not know how much risk there is that the virus could be spread from the feces of an infected person to another person,” the CDC says on its website. “However, they think this risk is low based on data from previous outbreaks of diseases caused by related coronaviruses, such as severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS).”
Also, “no studies have yet clearly demonstrated or refuted toilet plume-related disease transmission, and the significance of the risk remains largely uncharacterized,” according to a 2013 review of toilet plume research.
The Yangzhou University researchers still recommend people take precautions, both at home and in public restrooms, by closing the lid before flushing, cleaning the seat, and washing your hands after flushing.