Virus Throwers: High Levels of Aerosol in Public Toilets

Our waste products may be full of disease-causing bacteria and viruses. And that’s why we want to flush them as quickly as possible after using the toilet. However, a study conducted by Jesse Schreck of Florida Atlantic University in Boca Raton and his team shows that simply suppressing the flush in public toilets has the same side effect: when the water goes into the bowl, the force of pouring water Is formed and it happens that the turbulence produces a lot of aerosols that can carry pathogens with them. This is written by the scientists in the journal “Physics of Fluids”.

For the study, the team hung a toilet key and aerosol measuring devices at various heights around the urinal in a public toilet. They also measured the normal aerosol load in the toilet before and after the experiment. Within three hours, one of the participants pressed the flush 100 times, causing a significant increase in the aerosol concentration in the room. Computer simulations had already suggested that.

Each flush produced tens of drops, which rose 110 cm above the bowl and about 70 cm above the urinal. The average time in aerosol cloud air was about 20 seconds. After each flush, the number of drops increases by an average of 50 and 200 percent, depending on size, with researchers registering the largest increase in the class of medium aerosol sizes (0.5 to 7 micrometers in diameter).

However, various factors affected the extent of droplet haze, such as the size of the bowl, the pressure with which water shoots into the porcelain, or how hard the user is pressed on the rinse. A lid reduced the amount of aerosols – but did not completely stop them as they also found their way through gaps and cracks.

“Each flush of a toilet bowl and urinal produced a significant amount of droplets less than three microns in diameter. Siddharth Verma, who was involved in the study, says, “If there is a transmission of pathogens into the excretory products, it represents a considerable risk of transmission.”

This can be a problem, especially in times of epidemics, because public toilets are often heavy, small, and with poor ventilation. In addition to pathogens known for digestive diseases such as norovirus, saras-cove-2 has also been detected in feces. Improved ventilation system can at least improve the condition.