Loo etiquette has a new standard: put the toilet lid down as well as the seat, because leaving the lid up when flushing could lead to bacterial and viral transmission.
It sounds like the wisdom of a germaphobe, but it’s one of the findings in a new global review, published in Science of the Total Environment. The review determined that leaving the loo lid open after flushing might disperse contaminated droplets up to 1.5 metres, and these particles could hang around for up to 30 minutes.
Another review, published in Frontiers in Built Environment, found that the number of particles expelled by a toilet flush is equivalent to a person talking loudly for just over six-and-a-half minutes – the true definition of a potty mouth.
But the team found no evidence of airborne coronavirus transmission in public toilets.
“Some people have been worried about using public washrooms during the pandemic, but if you minimise your time in the bathroom, wash and dry your hands properly, and don’t use your mobile phone, eat or drink, then the risks should be low, especially if the bathroom is well maintained,” says co-author Professor Erica Donner of the University of South Australia.
“While there is limited evidence of COVID-19 transmission via public washrooms, they are rife with bacteria, especially those that are used frequently and not cleaned properly.”
The team also found that defective plumbing and uncovered rubbish bins could lead to a similar effect that increases the risk of a range of intestine, skin and respiratory bacterial and viral infections, especially from surfaces.
Because of this, the authors suggest shutting the lid as part of your post-toilet routine, along with rigorous handwashing and sanitisation.
“Although there is a potential risk of aerosols spreading from toilet flushing and hand drying, we found no evidence of airborne transmission of intestinal or respiratory pathogens in public bathrooms in the literature we reviewed,” explains Donner.
“However, there is no doubt that thorough handwashing and effective hand drying is critical in stopping the spread of diseases.
“As borders open up and cases increase, people can protect themselves against COVID-19 infection by continuing to practice good hygiene. This includes handwashing and sanitising, disinfecting door handles, toilet lids and other frequently touched surfaces.
“These habits will not only lower the risk of COVID-19 infection, but also limit the risk of bacterial infections.”
The review was conducted by the University of South Australia and the Australian National University with funding from Dyson Technology Ltd.
Deborah Devis is a science journalist at Cosmos. She has a Bachelor of Liberal Arts and Science (Honours) in biology and philosophy from the University of Sydney, and a PhD in plant molecular genetics from the University of Adelaide.
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