Close The Lid After You Skip To The Loo

Based on reports perhaps it is time to develop a new healthy sanitary habit, just as one covers their mouth when they cough or covers their nose before sneezing, one should be closing the lid before they flush to avoid releasing toilet plume.  Not to mention it is still most important to wash your hands before you exit the restroom. 

According to Philip Tierno who is a microbiologist at New York University small particles of waste mix with the water in the toilet after you flush which can shoot aerosolized feces as high as 15 feet into the air, every time you flush these bacteria could be spraying into the air to potentially make you sick. While older toilets are far worse at doing this than newer ones, it can still happen.  

A recent UK study published in the Journal of Hospital Infection has revealed that keeping the toilet open while flushing increases the risk of contamination on your person as well as on other areas of the bathroom. 

This study specifically examined for C.difficile which is a potentially life threatening bacterial infection that often spreads in hospital settings. This study simulated infected feces to measure how far it is aerosolized to spread into the air after flushing using two common types of hospital toilets to find C.difficile in the air 25cm above the toilet seat and determined that surface contamination occurred within 90 minutes of flushing which means that the droplets remain suspended in the air for some time before settling down on  a surface. 

These findings support those from other studies demonstrating how flushing domestic toilets and hospital toilets with the lid open can contaminate the surrounding surfaces with other types of bacteria such as E.Coli. 

Leeds University research tested the air above the toilet to find that C.difficile can be spewed up to 10 inches above the throne, these germs were found on the sides of the toilet, on the top and on the floor. The highest levels were found right after flushing, but even 90 minutes later contaminated droplets were detected on nearby surfaces. 

Another study published in the journal Applied Microbiology found that whatever you put down the toilet can stay there for a long time, finding that toilets dispersed microbes far enough to settle on other bathroom surfaces and they remained on the toilet porcelain after multiple flushes decreasing after a few but remaining until being cleaned. 

A recent review also found similar dispersion results, although this study did not find evidence to either support or deny disease transference through toilet plume and suggests that more research is required to gauge the dangers of aerosolized fecal particles in toilet plume. 

"Contaminated toilets have been clearly shown to produce large droplet and droplet nuclei bioaerosols during flushing, and research suggests that this toilet plume could play an important role in the transmission of infectious diseases for which the pathogen is shed in feces or vomit,” note the authors of a study published in the American Journal of Infection Control. "The possible role of toilet plume in airborne transmission of norovirus, SARS and pandemic influenza is of particular interest.”

According to a study published in the journal Physics of Fluids on June 16, 2020 the virus that causes COVID-19 can be found in the feces of those infected with the disease, and the findings from this study suggests that it can be transmitted through the use of toilets, according to the authors. The upward velocity of the toilet plume of the ejected droplets rose high above the seats with the simulations showing that flushing sent some dopplets nearly 3 feet into the air where they floated for over a minute where they can be inhaled or settle onto other surfaces. 

"One can foresee that the velocity [of upward-flowing aerosol particles] will be even higher when a toilet is used frequently, such as in the case of a family toilet during a busy time or a public toilet serving a densely populated area," study co-author Ji-Xiang Wang, of Yangzhou University in China, said in a journal news release.

Closing the toilet lid before flushing is also important for those going through chemotherapy, as the body will rid itself of most medications within the first 48 hours after treatment, and these drugs may be present in bodily fluids, exposure to these fluids can irritate your skin or the skin of others. The American Cancer Society recommends closing the lid before flushing, and flush it twice, and if possible use a separate bathroom from other family members during this time. 

In France there are 2 patients in the hospital who likely contracted Legionnaires disease after inhaling contaminated toilet water that was aerosolized during the flushing process, according to a recent report published in the journal Emerging Infectious Diseases on June 10, 2020 describing how the patients likely contracted the disease after staying in the same hospital room but 5 months apart. 

It has long been suspected that toilet plumes may spread disease, but this is the first time that a genetic analysis has linked patients’ infections with contaminated toilet water and Legionnaires’ disease with it being noted that the authors, "strongly suggesting that the toilet water is the source of the transmission," study lead author Dr. Jeanne Couturier, a medical biologist at the Saint-Antoine Hospital in Paris.

According to the CDC, Legionnaires disease is a serious lung infection, with the bacterium living in watery environments and becoming a serious health issue when it spreads in building water systems such as cooling towers, hot tubs, shower heads, sink faucets, and fountains. One can become infected after inhaling airborne water droplets that contain the bacteria, but it doesn’t typically spread from person to person. 

The investigation into the source found the bacteria in the toilet bowl water in the room but not in the shower or sink in the room, genetic analysis found the strains were either identical or closely related to the strains infecting the patients. Samples were taken from 29 other toilets in 5 different hospital buildings with none testing positive to determine if this was a widespread problem. The contaminated toilet was disinfected daily with bleach which was found to be effective at preventing Legionella growth, and no more samples from the toilet tested positive over the next 1.5 years. 

"It seems important to educate patients to close the toilet lid before flushing, particularly immunosuppressed patients or patients with comorbidities, who are more at risk of Legionnaires' disease," Couturier said.

"The bigger droplets and the aerosol likely don’t travel very far above or around the toilet, but very tiny droplets could remain suspended in the air for some time,” according to Dr. Janet Hill who is a microbiologist, "Since the water in the toilet bowl contains bacteria and other microbes from feces, urine and maybe even vomit, there will be some in the water droplets. Every gram of human feces contains billions and billions of bacteria, as well as viruses and even some fungi."

"Closing the lid reduces the spread of droplets,” Hill explained. "The chances of getting an infection from toilet aerosols is really, really low,” said Hill. “The vast majority of microbes in human urine and feces are completely harmless — and actually beneficial. If you were using a toilet that had also been used by someone with a nasty infection, like, say, they had diarrhea from salmonella or campylobacter infection, then the water might contain a very tiny number of these organisms. But in order to actually get infected, you would have to ingest bacteria that were still alive and ingest them in sufficient numbers to cause an infection. Bacteria won’t survive indefinitely in toilet bowls or on toilet surfaces, and getting the bacteria on your skin or clothes doesn’t mean that you will ingest it, and so you wouldn’t get infected.”

"There is little advantage to closing the toilet lid when you flush,” said microbiologist Dr. Bill Ghiorse. "The few microbes that could harm you are already there. The flushed material will be conducted to the sewers system efficiently leaving little chance for aerosolization, which is the only possible route for infection. You could hold your breath when you flush; but it is much more important to keep the toilet bowl clean and wash your hands after flushing.”

Despite Ghiorse’s skepticism this still is gross news to most, and there is still a chance of infection that most would like to avoid. Why not take the extra fraction of a second that it takes to close the toilet lid to increase your chances of not getting sick and improve your bathroom hygiene. Why not just close the lid, just in case because it is better to be safe than sorry, and as Dr. Hill so aptly puts it "Toilets have lids for a reason."