Here's why you should always close the toilet lid when you flush
You really should put the toilet seat down.
And while it may also put some household arguments to rest, the real reason to close the toilet lid is a phenomenon known as a "toilet plume."
When you flush a toilet, the swirling water that removes your waste from the bowl also mixes with small particles of that waste, shooting aerosolized feces into the air.
Low-flow toilets have decreased this risk — they don't gush or blast as much as other types of johns — but countless old toilets are still in use today and can really spew.
Philip Tierno, a microbiologist at New York University, says that aerosol plumes can reach as high as 15 feet.
"It is a good idea to lower the seat, especially if the bathroom is used by multiple people," Tierno told Tech Insider.
A study published in the journal Applied Microbiology in 1975 (before the adoption of low-flow toilets) found that whatever you put in your toilet can stay there long after you flush. After seeding a toilet bowl with potentially infectious bacteria and viruses, the researchers found that the toilet dispersed the microbes far enough to settle on other bathroom surfaces, like the floor, the sink, and even your toothbrush.