Is something about to explode? Researchers from the University of Colorado showed how flushing a … [+]
If you like watching what’s in the the toilet spiral down after you flush, urine trouble. A study recently published Scientific Reports showed that all of that icky stuff in the toilet may be going right back into your face. In fact, it may be going everywhere around the toilet. That’s because lasers showed that flushing a toilet without the lid generated a volcanic plume of stuff. And particles in this plume moved at a speed of two meters per second so that the whole Mount “Ick-orous” eruption rose to a height of over 1.5 meters within eight seconds. That’s rising roughly one Kylie Minogue, who is about five feet tall, which is slightly higher than 1.5 meters.
If that description alone is not enough to get your face flushed, take a look at the following video featuring John Crimaldi, PhD, the lead author on the study and a Professor of Civil, Environmental, and Architectural Engineering at the University of Colorado, and a toilet:
As you can see, for the study, the researchers created a sheet of laser light over the toilet. Every particle launched into the air from the toilet would then hit the sheet, resulting in a green color. One can see by the abundance of green that things over the toilet are full of sheet, so to speak. Yep, that faithful porcelain throne on which you’ve spent lots of quality time over the years may be looking more like Old Faithful the geyser now. The next time you flush you may want to make sure the toilet lid is closed first, lest some of that plume makes it right into your eyes, nose, and mouth. Sort of changes the meaning of potty mouth, doesn’t it?
This was certainly an interesting new way to use lasers that doesn’t involve laser tag. Crimaldi conducted this game of thrones research with Aaron C. True, PhD, Karl G. Linden, PhD, Mark T. Hernandez, PhD, Lars T. Larson, and Anna K. Pauls, all from the University of Colorado as well. At least one toilet was involved in the study too but apparently didn’t reach the level of authorship for the paper.
While the toilet simply gurgled throughout most of the video, Crimaldi did most of talking, offering a description of what happened post-flush: “[The toilet] emits these very small aerosolized particles, and they range from as small as tenths of microns up to potentially as large as almost a millimeter.” He added that, “The very large particles fall out quickly, the smaller particles remain suspended.” Hmm, that number two point raises the question about what could happens to the air in a bathroom, especially a poorly ventilated one after a toilet or toilets have been flushed multiple times in succession.
This study didn’t represent exactly what would happen in such a situation. Not surprisingly, for the study, the researchers didn’t flush the toilet after someone had actually used it. That would have been quite disgusting and would have required the researchers to provide toilet paper. Instead, the bowls simply had tap water without any solid stuff before the flushing was commenced. The researchers did note that the presence of poop and toilet paper could have altered the plume dynamics in unanticipated ways.
Bathroom stalls may have very limited ventilation, which can affect the dynamics of the plume … [+]
Additionally, the researchers didn’t conduct the study in an actual public restroom. Instead, they place the toilet in the middle of a 300 m3 open laboratory area that was fairly well-ventilated, which is probably not the kind of set-up you typically have to pee and poop. If you tend to use a typical public restroom bathroom stall, there may be less air circulation, which could in turn affect the size and duration of the plume. Alternatively, if you tend to use a toilet in a better ventilated location such as a wind tunnel, on top of an SUV in motion, or on top of second base in Wrigley Field during a Chicago Cubs game, the prevailing conditions would probably affect the plume dynamics in other ways.
Regardless, this University of Colorado study wasn’t the first to tell you to beware the air after flushing. Back in 2020, I reported for Forbes findings that may have gotten you to mind your pees and Q’s. My article included results that were generated by a computer model of a urinal and were published as a research letter in the journal Physics of Fluids. This model had shown that a urinal may be able to generate a particle plume that can reach a height of 0.84 meters, which is about 2.75 feet. And, as I had said back then, since Bruno Mars is listed as 5’5” tall, that then would mean that particles could travel halfway to Mars.
A computer model has shown that a urinal may be able to generate a particle plume that can reach a … [+]
So what can you do about this number one and number two problem? Well, for your toilet at home, you can simply do what your significant other has been urging you to do all along: close the lid. Shut it before flushing unless you want some poop-aromatherapy around.
It’s not such an open-and-shut case with public toilets, though. Many public toilets do not even have lids that you can close. Plus, even if they did have did, would you be telling all the strangers, “Hey, make sure you put down the lid.” Therefore, Unless you wear deep-sea diving gear every time you walk into a public restroom, who knows what may be hanging in the air and flying into your face.
The big question is whether there are any real health concerns about such a situation. Is this just an icky, oh-poo thing? Or can you catch some kind of disease when poop there is? Well, as the Covid-19 pandemic has demonstrated, some pathogens can be transmitted via small aerosolized droplets. It’s unclear though how many of these pathogens can be transmitted via toilet spray. Even if there are pathogens in the spray, are there actually enough in the air to cause an infection in a human? These are unanswered questions because the whole “Can toilets spread infectious disease” thing didn’t seem to be a number one, or even a number two question, previously before 2020. In other words, not many people may have given a poop about answering this question. Perhaps the Covid-19 pandemic has since changed our priorities, showing that it may be time to get to the bottom of all this. You never know when a new pathogen may come around with the ability to spread in such a manner. And society can’t be caught with its pants down again.
One obvious question is whether public bathrooms need better air ventilation and purification systems. Simply walking into any number of public restrooms will probably prompt you to answer, “Yes.” A Summer’s breeze likely isn’t the first thing that comes to mind when you think of public restrooms.
The other question is whether more effort should be made to re-evaluate toilet design? Chances are you won’t find too many people who will say that spraying a plume of poop into the air is a good thing. It seems like people and companies are spending way too much time finding new ways for people to send poop emojis to each other. Why not re-direct some of these efforts towards designing better toilets. The University of Colorado researchers did mentioned some possibilities such as finding ways to reduce the strength or change the direction of the water jet. One shouldn’t assume that the current design is the best way to go with no room for improvement. In other words, what we have now shouldn’t be considered a royal flush.
