As the world’s population continues to cope with the coronavirus pandemic, scientists are eager to discover the ways in which the virus can spread. While the primary method of transmission remains being in proximity to an infected person, research is now showing that bathroom fixtures can be potentially hazardous.

Specifically, the toilet.

Toilets have always been a source of potential contamination, because flushing spews viral and bacterial particles nearly 3 feet in the air. In the age of coronavirus, that risk has taken on a new meaning. In a story for The New York Times, Knvul Sheikh reports that there’s growing evidence a flushed toilet can create an aerosolized cloud of infectious particles. This coronavirus danger zone can then linger, inviting inhalation by the next person to use the facilities.

According to a study published in the journal Physics of Fluids, the concern stems from the presence of the virus in feces. While it’s primarily a respiratory illness, coronavirus can also take up residence in the small intestine and cause digestive illness. Once the virus is excreted in human waste, the action of flushing the toilet can eject the particles upward. The motion of the incoming water creates a vortex, displacing air and acting as a germ cannon.

While it’s clear the virus does get dispersed by flushing, scientists don’t yet know how much infectious virus may be contained in these clouds. The best thing to do is to close the toilet lid before flushing, which should mitigate a lot of airborne contaminants. Household members who are sick should use a separate bathroom if possible.

Public bathrooms are trickier, as they’re used by a great many more people and don’t often have lids to close. For now, it may be best to avoid these restrooms if you can. Wearing a mask may also reduce some of the risk. And always wash your hands.

[h/t The New York Times]