It’s something we all do every day, but a new study might make you reconsider your approach the next time you flush the toilet.
Scientists from Flinders University have warned that flushing toilets can release particles into the surrounding air at heights equivalent to the ‘breathing zones’ of adults.
The team reviewed more than 20 previous studies on aerosols and bioaerosols released during toilet flushing.
They say the findings highlight the importance of closing the toilet lid before flushing.
Lira Adiyani, lead author of the study, is sad: ‘Toilet flushing causes turbulence that can release aerosols into the surrounding air.
‘Some studies have detected these aerosols at the breathing level of adults, suggesting a possible route of exposure through inhalation.’
It’s something we all do every day – but a new study could make you reconsider your approach the next time you flush the toilet
After flushing, airborne particles were detected up to 6 feet (150 cm) from the toilet horizontally, and up to 5.3 feet (163 cm) vertically
For the study, the team wanted to understand exactly what happens when you flush the average toilet.
“During rinsing, water collides with surfaces at high speed and causes turbulence, creating droplets that can become airborne and remain suspended in the air as aerosols,” they explain in their study, published in Science of the total environment.
‘These droplets can contain micro-organisms from both the water and the user.
‘Since toilet flushing is a routine activity, understanding the formation and dispersion of these aerosols is important for characterizing indoor exposure routes and associated health risks.’
The researchers analyzed 22 previous studies on toilet flushing and found several common themes.
After flushing, airborne particles were detected up to 150 cm (60 in) from the toilet horizontally, and up to 163 cm (5.3 ft) vertically.
“Vertically, particles were observed to rise higher than 100 cm above the floor, with the maximum reported height reaching 163 cm, which may be within the typical breathing zone of adults,” they explained.
Disgustingly, these aerosols would remain in the air for at least 20 seconds even after flushing.
Disgustingly, these aerosols lingered in the air for at least 20 seconds after flushing
As for the microbes themselves, the studies highlight a range of nasty bugs found in toilets, including E.coli, Salmonella and Clostridium difficile.
Ms Adiyani explains: ‘The microbes can come from contamination of the toilet bowl during use as well as from the water used for flushing.
‘The more microbes there are in the toilet, the more bioaerosols can be released.
‘Larger flushing volumes therefore generally produce more aerosols.’
Based on the findings, the researchers recommend always closing the toilet lid before flushing.
“I would recommend closing the toilet lid before flushing, if a lid is available, as a precaution to minimize potential exposure through inhalation – while recognizing that this does not completely prevent aerosols from escaping,” Ms Adiyani added.
