Close the Toilet Lid When You Flush
Not so much in USA and Canada?
I want to know how many people "do" it here.
In the field of science (yep, there's science about this!), it's called the "toilet plume," a.k.a. the germs and fecal matter that get shot upwards — up to 15 feet high! — with the force created by the sudden gush of water.
"Research suggests that this toilet plume could play an important role in the transmission of infectious diseases for which the pathogen is shed in feces or vomit," the scientists wrote in the American Journal of Infection Control. "The possible role of toilet plume in airborne transmission of norovirus, SARS, and pandemic influenza is of particular interest."