Is it true that if you do not lower the toilet cover when washing off, bacteria from it fall on other surfaces of the bathroom?

There is an opinion that if you press the button for draining the water in the toilet without closing the cover, the smallest water particles can fly around the restroom, and the bacteria from them are settled on the toothbrush, the door handle and other objects. We decided to check whether such fears have reasons.

The fact that before washing you need to lower the toilet lid is written by the media (for example, "Gazeta.ru","New hearth" And "Moscow Komsomolets"). Popular Articles on this topic on specialized resources dedicated plumbing, and also home And everyday life. Users social networks, forums And Platform blog They discuss on the topic whether it is necessary to wash off the water in the toilet with a dropped lid. Site visitors questions And answers They are also interested in need to whether to do it and if so, then For what. 

Through the fecal-oral path of distribution transmitted Many different diseases: parasites, hepatitis A, rotavirus, novirus, coronavirus, influenza, dysentery, etc. Moreover, some of them may not even guess some of them, already being a carrier of the pathogen. Of course, no one wants to find this “bouquet” on their toothbrush. But can viruses and bacteria really get there when washing water in the toilet? 

Since the mid-1970s, microbiologists warnedthat yes, they can. During the washing of the water, part of the content of the toilet is spilled out - in the form of both large drops and a fine water suspension, which is not visible to the naked eye, but remains in the air for quite some time and can settle on all surfaces of the bathroom. Including such small drops found on a toothbrush if the bathroom is combined, as well as on others surfaces: bath, towels, door handles, toilet paper holder, etc.

In 2022, scientists from the University of California at Boulder (USA) conducted experimentTo measure the speed and trajectory of the movement of these small particles flying out of the toilet when washing off, and at the same time show to people that this is not a joke at all. They installed in a public toilet not equipped with toilet covers, lasers and cameras that recorded aerosol particles when washing off. It turned out that the water suspension breaks out of the toilet at a speed of 2 m/s to a height of up to 1.5 m for 8 seconds. After draining water. Moreover, if large drops settled quickly, then the aerosol can remain in the air and spread for several minutes (which is especially true for public toilets, where visitors usually change often).

Researchers from the University College of Cork (Great Britain) in 2019 Studied The composition of the air in the public toilet for a week. Bioerosol sensors recorded the quantity and size of particles present in the air, as well as the content of bacteria in them. It turned out that when the toilet cover was closed before washing off, the amount of bacteria in the air was less than 30-60%. True, at the same time, the size of the drops and the concentration of microorganisms in them also increased, moreover, they were 11 minutes longer in the air. Scientists did not specify how exactly this is affected by the closed cover. 

In 2021, Chinese scientists conducted review The existing scientific literature on this topic also came to the conclusion that the aerosol from the toilets emitted during washing out, threatens people's health, especially in public toilets or when living together with an infected person. The closed toilet cover, according to the studied scientific work, on the contrary, seriously reduced these risks.

Returning to tooth brushes: the American Society of Microbiology in 2015 conducted study At the University of Queennip (USA), having studied the brushes of students living in a hostel and using common bathrooms. Fecal bacteria were found on 60% of brushes. It is especially dangerous, researchers emphasize that in public bathrooms it can be particles of other people's excrement with pathogenic microflora, an unfamiliar to the body of a particular person. Potentially, this can lead to the spread of infections. Scientists did not specify how the bacteria fell on the tooth brushes, however, based on the observations described above, it can be assumed that at least some of them originally spread in the form of aerosol when draining water in the toilet with an unclosed lid. 

Although there are studies that indicate that inhalation or involuntary swallowing of such microparticles can lead to serious diseases, there are experts who disagree with this. So, Professor Kelly Reynolds from the University of Arizona He thinksthat if visitors to the toilet are not sick with infections transmitted fecal-oral way, then, most likely, there will be no particular harm from inhalation or swallowing aerosol. American Dental Association claimsthat so far there is no convincing evidence that fecal bacteria on the toothbrush are really able to somehow negatively affect human health.

Thus, if you do not close the toilet cover during the drain of water, the smallest water particles contaminated with bacteria, which are found in excrement, can break out of it, be in the form of suspension in the air for some time, and then settled on the surrounding surfaces. This can potentially lead to the spread of infections, especially when it comes to public toilets. At the same time, the lowered cover also does not protect from this “toilet train” by 100%, however, according to the studies, it significantly reduces the number of such particles. 

Photo on the cover: canva.com

Is it true

What do our verdicts mean?

Read on the topic:

1. Is it true that, sitting on a public toilet, you can catch many diseases?
2. Is it true that before cooking the shell of chicken eggs, you need to wash so as not to get salmonelle?
3. Is it true that you need to brush your teeth before breakfast so as not to swallow bacteria?
4. Is it true that there are more bacteria in the human body than cells of the body itself?