They are invisible to the eye, but scientists have now managed to show them by shining a green laser. When you flush the toilet, it sprays up a cloud of water particles that may contain infectious agents. When the researchers at the University of Boulder in Colorado flushed the toilet in their lab, they were struck by how quickly the particles spread, and how far they travel.
– Studies have shown that the infectious agents remain in the toilet despite being flushed several times, says John Crimaldi, professor at the University of Boulder.
Now it is hoped that this will influence how toilets are designed in the future, especially the public ones that often lack lids.
See the lab test in the player above