Surprised this factoid has not become common knowledge yet1- simple enough to close (both) lids of the toilet before flushing, otherwise all sorts of fecal matter float around in your bathroom. A few years ago, saw an exhibit at the Peggy Notebaert Nature Museum that actually demonstrated this with black lights and a model bathroom. I’ve closed the lid ever since.
Cecil Adams of the Straight Dope wrote:
I read somewhere years ago that when you flush the toilet with the lid open, a plume of contaminated water droplets is ejected into the air and lands on everything in the bathroom, including (yuck) your toothbrush. Women I mention this to nod knowingly, but among men it is met with scorn, the common view being that this is another female scare story intended to “get us to put the top down.” Knowing your ability to rise above petty considerations of gender, I turn to you.
— Katie Wolf, Toledo, Ohio
Opinions on this topic do seem to break down along male-female lines. “Toilet water on your toothbrush!” my assistant Jane howled. “That’s gross! That’s disgusting!” “Yeah,” said Little Ed, “it’s got Straight Dope written all over it.”
You remembered right about toilet plume, although I think toilet “aerosol” is probably the more accurate term. No doubt you saw something about Charles Gerba, a professor at the University of Arizona who specializes in environmental microbiology. For those of you with a romanticized picture of the academic life, I should tell you this means he spends a lot of time crawling around public toilets and has had the cops called on him twice.
In 1975 Professor Gerba published a scientific article describing the little-known phenomenon of bacterial and viral aerosols due to toilet flushing. The more you learn about it, the scarier it sounds. According to Gerba, close-up photos of the germy ejecta look like “Baghdad at night during a U.S. air attack.” The article ominously depicts a “floor plan of experimental bathroom with location of gauze pads for viral fallout experiments.” A lot of virus fell on those gauze pads, Gerba found, and a lot of bacteria too. In fact, significant quantities of microbes floated around the bathroom for at least two hours after each flush.
(click here to continue reading The Straight Dope: Does flushing the toilet cause dirty water to be spewed around the bathroom?.)
- like I’ve noticed that sneezing into one’s sleeve instead of one’s hand has become more common practice recently [↩]