Have you ever thought about whether you lower the toilet lid before flushing or leave it open? A new study conducted by researchers at Asan Medical Center in South Korea may change your mind about this!
Scientists have long established that when a toilet is flushed, tiny droplets of water, as well as particles of urine, feces, and pathogenic microorganisms, are released into the air. To determine how dangerous flushing is, in 2022, researchers from the University of Colorado Boulder used lasers to analyze the invisible aerosol cloud formed when using a commercial toilet without a lid.
As a result, they found that a cloud is formed during flushing that moves at a speed of over 2 m/s and reaches a height of 1.5 m in just eight seconds.
To protect patients in hospitals and minimize the spread of bacteria present in toilets, researchers at Asan Medical Center developed an automatic flushing device that operates only with the lid closed.
“We must use all available means to combat infections to ensure maximum safety and health for patients, especially those who are at risk,” stated Jihai Park, the lead author of the study.
Methodology of the Experiment
To study the spread of microbes generated during toilet flushing, the authors installed their device in four toilets in the hospital that were used by patients. An additional four toilets without this device served as the control group. Eight Petri dishes with agar, intended for cultivating microorganisms, were placed on top, in front, on the sides, and behind the toilet.
Each toilet was flushed once after preliminary cleaning. Particles in the air were allowed to settle on the surfaces of the Petri dishes with agar for 90 minutes. The dishes were incubated for two days, after which the researchers analyzed which colonies of bacteria had formed. On average, the surfaces around toilets with automatic flushing devices registered two times fewer colonies of bacteria—6 compared to 14—compared to toilets without such devices.
This study highlights the importance of closing the lid before flushing and installing automatic flushing devices to reduce surface contamination in bathrooms. In the near future, scientists plan to install automatic flushing devices in all hospital toilets, as well as devices for automatic ultraviolet disinfection, to reduce the risk of infection spread.
