While the (mostly American) argument of putting the toilet seat down after you’re done taking a leak has annoyed the rest of the world since the dawn of TV, there’s now a fair number of people clamouring to get people to also put the toilet lid down when they flush. At first, I was like, “Why man? I mean it’s not like we’re in some kind of Bizarro parallel universe where a toilet flushes upwards and the only way to protect yourself is to keep the lid down.”

Turns out however, that there’s a perfectly logical and scientific reason to be putting the lid of your commode down while you flush, and it has nothing to do with parallel universes.  

Basically, when you flush, the gushing water mixes with small particles of toilet waste and shoots aerosolized faeces, known as a toilet plume, into the air. Yup, you got poop particles on your face foo!

If you’ve ever stared into the soul of that sweet toilet bowl while it flushes, you may have exposed yourself to a bunch of different germs and viruses. 

“The toilet plume may contain fecal bacteria, as well as other microorganisms that may be present in these substances, such as certain viruses,” says Amesh Adalja, M.D., an infectious disease specialist in Pittsburgh. This cloud of nastiness was first discovered in 1975 by microbiologist Charles Gerba after he put germs in a toilet to test if they still survived after flushing. The main bacteria found in the plume is E. coli, which can cause abdominal pain and diarrhoea. 

Studies are ongoing, but some say the germs in the plume spray can even reach your sink and toothbrushes.

All of this can be avoided to a large degree by just putting the toilet seat down while you flush though, so let’s try to make that a habit, and never float on poop clouds again!