According to a study published in the Physics of Fluids, using public toilets could increase your risk of contracting coronavirus.
Women's Health UK explains how this works, "If an infected person should use a toilet before you, in flushing, via their poo, they might generate a cloud of infected aerosol that hits the surrounding air. This could be ready for you to inhale when you enter the bathroom, and could potentially linger on nearby surfaces, which you might touch."
The study explains, "40%–60% of particles reach[ing] above the toilet seat, leading to large-scale virus spread."
With that in mind, avoiding public toilets when possible is a smart idea if you are concerned.
However, there are some precautions you can take to reduce the risk of contracting the virus in public restrooms.
First, the article recommends putting the lid down before flushing to prevent the particles getting outside of the toilet bowl.
Additionally, the article recommends cleaning the toilet seat before using it "since floating virus particles could have settled on its surface."
Lastly, make sure to wash you hands carefully after using the toilet to prevent contracting the virus through any particles that might be present on the lever or door handle.