Everyone tries to be extra careful when using public restrooms. What many do not know, however, is that it is not necessary to get in touch with the hygienic services to contract diseases, even very dangerous ones. Often it is enough to breathe in the aerosols that form in the air. Here’s what scientists from Florida Atlantic University’s College of Engineering and Computer Science recently discovered. The danger of public toilets
In public toilets, unfortunately, there is an innumerable amount of pathogens – and not only in the surfaces that are often cleaned, but also in the air. The problem is due to the toilet flushing, which generates an incredible amount of aerosols containing viruses and bacteria. Depending on the model of the toilet and the water pressure, the concentrations can be more or less high. When dispersed to a great extent, such aerosols can cause severe food poisoning, covids, noroviruses, and even Ebola. Public toilets and coronavirus
Even in a pandemic era, there are not many limitations regarding the use of public toilets and since the virus has also been found in stool and urine samples it goes without saying that the possibility of contagion is real in shared toilets. To investigate the subject, the team of scientists investigated the physics of fluids generated by a toilet flush. To measure the droplets, they used a particle counter positioned at various heights of the toilet (or urinal). In this way they were able to capture the number of droplets generated during the discharge and their relative dimensions. From the results – recently published in Physics of Fluids – it emerged that public toilets act as real hotbeds for the transmission of multiple diseases.Covid and other diseases in public toilets. The test results
“After about three hours of testing involving more than 100 rinses, we found a substantial increase in the measured aerosol levels in the surrounding environment with the total number of droplets generated in each wash test ranging up to tens of thousands. Both the toilet and the urinal generated large amounts of droplets less than 3 micrometers in size, posing a significant risk of transmission if they contain infectious microorganisms. Because of their small size, these droplets can stay suspended for a long time, ”said Siddhartha Verma, Ph.D., co-author and assistant professor in FAU’s Department of Ocean and Mechanical Engineering. It is important to point out that the droplets were found up to 1, 5 meters high for a minimum of 20 seconds after using the toilet. If the toilet was closed the amount of aerosol was less but not significantly.The ventilation system in public restrooms can help
“The noticeable accumulation of aerosolized droplets generated by the exhaust suggests that the ventilation system was not effective in removing them from the enclosed space even though there was not a noticeable lack of airflow within the bathroom. In the long term, these aerosols could rise with updrafts created by the ventilation system or by people moving around in the bathrooms, ”added Masoud Jahandar Lashaki, Ph.D, co-author and assistant professor in the Department of Civil, Environmental and Geomatic Engineering. of the FAU. The increase in such particles was exponential: by 69.5 percent in the levels measured for particles between 0.3 and 0.5 micrometers in size, by 209 percent for particles ranging in size from 0, 5 and 1 micrometers and a 50 percent increase for particles between 1 and 3 micrometers in size. It should be remembered that not only very fine aerosols are dangerous but also larger ones pose a risk in poorly ventilated areas, even if they experience stronger gravitational settlement. ‘They often evaporate rapidly in the surrounding environment and the consequent decrease in size and mass, or the eventual formation of droplet nuclei, can allow microbes to remain suspended for several hours. The study suggests that incorporating adequate ventilation into the design and operation of public spaces would help prevent aerosol build-up in high-occupancy areas such as public restrooms. The good news is that it may not always be necessary to review the entire system, since most buildings are designed for certain codes. It may just be a matter of redirecting the airflow based on the bathroom layout, ”said Manhar Dhanak, Ph.D., co-author, chair of the FAU Department of Ocean and Mechanical Engineering and professor and director of SeaTech. It is important to note that the bathroom was thoroughly cleaned and closed 24 hours prior to conducting the experiments, with the ventilation system functioning normally. chair of the FAU Department of Ocean and Mechanical Engineering and professor and director of SeaTech. It is important to note that the bathroom was thoroughly cleaned and closed 24 hours prior to conducting the experiments, with the ventilation system functioning normally. chair of the FAU Department of Ocean and Mechanical Engineering and professor and director of SeaTech. It is important to note that the bathroom was thoroughly cleaned and closed 24 hours prior to conducting the experiments, with the ventilation system functioning normally.
“Aerosolized droplets play a central role in the transmission of various infectious diseases, including COVID-19, and this latest research from our team of scientists provides further evidence to support the risk of infection transmission in confined and poorly ventilated spaces,” he concludes. Stella Batalama, Ph.D. of the College of Engineering and Computer Science. Scientific sources
Jesse H. Schreck, Masoud Jahandar Lashaki, Javad Hashemi, Manhar Dhanak, Siddhartha Verma. Aerosol generation in public restrooms . Physics of Fluids, 2021; 33 (3): 033320 DOI: 10.1063 / 5.0040310
Flushing a public toilet
Don’t linger, since aerosolized droplets do – FAU
