Will shutting the toilet lid when you flush really keep nasty microbes from leaving the bowl and spraying all over the place? Well, it’s not exactly an open and shut case, according to a new study published in the American Journal of Infection Control. The study found that the floor and walls around the toilet could still go quite viral, so to speak, even when the lid stays down during the flush. Yes, even the walls around the toilet ended up getting contaminated with viruses from the toilet bowl.
For the study, a team of researchers from the University of Arizona (Madison P. Goforth, BS Stephanie A. Boone, PhD Justin Clark, MS Priscilla B. Valenzuela, MS, FRSPH, and Charles P. Gerba, PhD) and Reckitt Benckiser, LLC, the makers of Lysol (Julie McKinney, PhD, and M. Khalid Ijaz, DVM, PhD) dumped some bacteriophage MS2 into two different types of toilets:
- A public toilet: This was situated in a stall in a public restroom that served an office building. The toilet was doing a tankless job, meaning that the toilet didn’t have a tank. Instead, the water used for flushing came from an attached water line. The toilet seat was U-shaped and had a gap in its front.
- A home toilet: This was a standard siphonic toilet that had a water tank but no gap in the seat. The toilet was situated in the bathroom of a residential home.
Why would researchers dump bacteriophage—a virus that can infect bacteria—into a toilet? After all, it’s not everyday that a guest will ask, “Where’s your toilet so that I can put a bunch of bacteriophage into it?” Well, this particular bacteriophage can serve as a good model for viruses that can cause gastroenteritis such as norovirus. It can spread in a similar manner but won’t cause the same type of disease in humans.
Once the bacteriophage was in the bowl, the researchers went about their flushing. They flushed the toilets multiple times, sometimes with the lids up, sometimes with the lids down. Then the research team took samples of the toilet water, the toilet seat, the floor around the toilet, and the adjoining walls. They cultured these samples and looked for the bacteriophage.
The results might bowl you over. The lids appeared to make no real difference in how much of the bacteriophage made it out of the bowl and onto the toilet seat, floor, and walls. That’s right, even with the lid down, the areas around the toilet got contaminated. Not surprisingly, the concentration of viruses was highest on the bottoms of the toilet seat. On average, the bottoms of the toilet seats had greater than 107 PFU/100 cm2 viral contamination. Think about that the next time you try to lick your toilet seat.
Clearly, what’s happening in Las Toilet may not stay in Las Toilet, even with the lid down. Therefore, as part of the study, the research team also checked what happened after they cleaned the toilet bowls with a bowl brush with and without hydrochloric acid, which can serve as a disinfectant. Brushing with hydrochloric acid made a big difference, decreasing contamination of the toilet bowl water by over 99.99% and the brush by 97.64%. So, if you want to keep your toilet from becoming a virus sprinkler, you may want to use disinfectant in your toilet bowl.
The results from this study is another reminder that your toilet is flush with possibilities around it. The toilet can become quite a geyser of pee, poop, pieces of fruitcake and whatever else is in the toilet once you press the handle. This means that it is not a great idea to stare at the water whirlpooling down after your flush it, no matter how mesmerizing that may be. It is also yet another a reason to regularly disinfect the toilet and the surrounding areas, including the walls. It is a good way to prevent you and your housemates from getting sick and can help you keep your friends.
