New Study Finds Closing Toilet Lid Does Not Prevent Spread of Germs

TUCSON, Ariz. – Should you close the toilet lid before you flush? It’s an ongoing debate that has left many questioning which option is more hygienic. However, a recent study conducted by microbiologist Charles Gerba and his team at the University of Arizona may settle this dispute once and for all. Contrary to popular belief, their research suggests that closing the lid does not effectively prevent the spread of dangerous germs.

In the study, published in the American Journal of Infection Control, the researchers discovered that the act of flushing a toilet creates a powerful force that propels microscopic viral particles into the air and onto nearby surfaces. Surprisingly, whether the lid is open or closed seems to have little impact on this dispersion. The only effective way to minimize the spread of viral pathogens, such as norovirus, is through regular disinfection of the toilet, toilet water, and surrounding surfaces.

Previous studies have focused on bacteria contamination in public restrooms and the importance of closing the lid to prevent the emission of a germ-laced plume. However, this new study specifically examined smaller viral particles in both residential and public restrooms. The results indicated that lid closure had minimal effect on the overall viral contamination, although it may influence the trajectory of the aerosol plume.

Gerba, who has dedicated nearly half a century to studying toilet germs, emphasized the importance of thorough cleaning. Even if the lid is closed, there is still a need to sanitize the toilet seat and other restroom areas regularly. This is particularly crucial in preventing norovirus outbreaks, which have been linked to aerosolized plumes from toilet flushes on cruise ships, flights, and schools.

The study involved testing toilets in both residential and public settings, comparing lid closure and open flushing. While lid closure did result in slightly higher contamination on some sides of the toilet, overall viral contamination remained unchanged. The researchers also noted that cleaning the toilet bowl with a disinfectant, in addition to using a brush, reduced contamination levels on nearby surfaces.

In light of these findings, experts recommend homeowners regularly clean and sanitize toilets and adjacent surfaces. Gerba advises keeping disinfectants and wipes near the toilet and thoroughly washing hands after each use. Additionally, individuals should exercise caution when a household member has diarrhea, as this can heighten the risk of exposure to norovirus and salmonella, necessitating increased cleaning and disinfection.

While public restrooms may not be subject to the same level of control, individuals can still protect themselves by practicing good hand hygiene and utilizing hand sanitizer. Furthermore, in order to minimize contact with bacteria and viral particles, it is advisable to avoid handling personal items such as toothbrushes and cosmetics in the bathroom.

As the debate rages on, one thing remains clear: regular cleaning, disinfection, and diligent handwashing are key in combating the spread of germs, regardless of whether you choose to close the lid or leave it open. So, the next time you reach for the toilet flush, make sure you’re taking the necessary steps to keep yourself and others safe from harmful pathogens.