Findings from Flinders University Research
Researchers at Flinders University in Australia reviewed 22 studies and found that flushing a toilet propels tiny droplets containing bacteria and viruses into the air, reaching the height at which people normally breathe. These aerosolized droplets can linger airborne for more than 20 seconds and rise over 1.5 meters. The study revealed that a tenfold increase in microorganism concentration in the water results in approximately a 2.6-fold increase in airborne aerosols. Additionally, increasing the flush volume by one liter raises aerosol concentration in the air by about 1.3 times.
Hygiene Recommendations and Additional Insights
The flushing process generates turbulence that lifts microscopic droplets from the toilet bowl. The droplet sizes mainly range from 0.3 to 10 micrometers, with most under 3 micrometers. Notably, a 2024 experiment demonstrated that closing the toilet lid does not fully prevent viral contamination of surfaces. In 2022, scientists from the University of Colorado used laser technology to show that toilet aerosols can reach nearly 1.5 meters in height within 8 seconds of flushing.
Based on these findings, experts advise the following precautions:
- Regularly cleaning toilets;
- Washing hands thoroughly after use;
- Using lower water volumes during dual flushes when possible;
- Implementing engineering controls in hospitals and high-risk environments.
Given the evidence, I recommend closing the toilet lid before flushing when available as a precaution to reduce inhalation of aerosols, although it does not completely prevent aerosol escape.
Lyra Adiani
These discoveries highlight the critical role of maintaining strict hygiene, especially amid ongoing public health concerns like pandemics. Following these scientific recommendations can help minimize infection risks in public spaces and healthcare facilities. The adoption of advanced technologies and engineering solutions has the potential to significantly improve safety in these environments.