A new study has found that flushing toilets release particles into the air, reaching the "breathing zone" of adults, where they can remain suspended for at least 20 seconds. Researchers also noted that closing the toilet lid might not be sufficient to prevent a "plume" of potential pathogens from escaping.
The findings come from a review of 22 studies on toilet-generated aerosols by Flinders University researchers, published in the Science of the Total Environment journal. They discovered that microbes from flushing water or bowl contamination become aerosols, with more "turbulent" flushing releasing a greater volume of particles.
These bioaerosols can contain biological material capable of transmitting pathogens such as legionella, influenza, and norovirus. While there are differing reports on whether Covid spreads through toilet aerosols, the researchers observed that higher water microbe levels and increased flush turbulence led to more suspended particles. However, the effects of bathroom ventilation and lid position were unclear.
Despite the uncertainty regarding lid effectiveness, lead author Lira Adiyani still recommends closing the lid as a precautionary measure. Co-author Harriet Whiley stated that people generally do not need to worry in their own homes unless someone is immunocompromised, with the team focusing on "protecting the most vulnerable through good design" in settings like hospitals and aged care.