It’s something we all do on a daily basis – but a new study might make you rethink your approach next time you flush the toilet.
Scientists from Flinders University have warned that flushing toilets can release particles into the surrounding air, at heights corresponding to adults’ ‘breathing zones’.
The team reviewed more than 20 previous studies into aerosols and bioaerosols generated during toilet flushing.
They say the findings highlight the importance of closing the toilet lid before you flush.
Lira Adiyani, lead author of the study, sad: ‘Toilet flushing creates turbulence that can release aerosols into the surrounding air.
‘Some studies detected these aerosols at adult breathing height, indicating a potential pathway for inhalation exposure.’
It’s something we all do on a daily basis – but a new study might make you rethink your approach next time you flush the toilet
After flushing, airborne particles were detected up to 4.9ft (150cm) away from the toilet horizontally, and up to 5.3ft (163cm) vertically
For the study, the team set out to understand exactly what happens when you flush the average toilet.
‘During flushing, high–velocity water impacts surfaces and creates turbulence, generating droplets that can become airborne and remain suspended as aerosols,’ they explained in their study, published in Science of The Total Environment.
‘These droplets may contain microorganisms originating both from the water and the user.
‘Since toilet flushing is a routine activity, understanding the generation and dispersion of these aerosols is important for characterising indoor exposure pathways and associated health risks.’
The researchers analysed 22 previous studies on toilet flushing, and found several common themes.
After flushing, airborne particles were detected up to 4.9ft (150cm) away from the toilet horizontally, and up to 5.3ft (163cm) vertically.
‘Vertically, particles were observed to rise beyond 100cm above the floor, with the maximum reported height reaching 163cm, which may fall within the typical adult breathing zone,’ they explained.
Disgustingly, these aerosols were also reported to remain suspended in the air for at least 20 seconds after flushing.
Disgustingly, these aerosols were also reported to remain suspended in the air for at least 20 seconds after flushing
In terms of the microbes themselves, the studies highlight a range of nasty bugs found in toilets, including E.coli, Salmonella, and Clostridium difficile.
Ms Adiyani explained: ‘The microbes can originate both from contamination of the toilet bowl during use or from the water used for flushing.
‘The more microbes present in the toilet, the more bioaerosols may be released.
‘Therefore, larger flush volumes generally produce more aerosols.’
Based on the findings, the researchers advise always closing the toilet lid before you flush.
‘I would recommend closing the toilet lid before flushing, where a lid is available, as a precautionary measure to minimize potential inhalation exposure – while recognizing that it does not completely prevent aerosols from escaping,’ Ms Adiyani added.
