Overview
- A Flinders University systematic review of 22 studies published this week consolidated evidence that flushing can launch aerosols that reach about 1.5 m horizontally and up to about 1.63 m vertically, which can put particles at typical adult breathing height.
- The review found aerosols can remain suspended for at least 20 seconds after a flush and that some captured particles contain microbes reported in toilet waste, including E. coli, Salmonella and C. difficile.
- Higher microbial concentration in the bowl and larger flush volumes were consistently linked to greater aerosol and bioaerosol concentrations across the studies reviewed.
- Authors recommend simple precautions — close the lid where available, wash hands, clean toilet surfaces regularly and ensure good bathroom ventilation — while noting lids and ventilation may not fully prevent aerosol escape.
- The paper highlights wide variation in methods and results across studies and calls for standardised measurements, targeted real‑world experiments and engineering design changes for high‑risk settings such as hospitals and systems using recycled water.