Put Down that Lid

A new UK study, published in the Journal of Hospital Infection,1 reveals that an open toilet lid during flushing increases the risk of contamination of other areas of the bathroom. The study specifically looked at Clostridium difficile (C. difficile), a potentially life-threatening bacterial infection often spread in hospitals. The researchers simulated bacteria-infected feces to measure how far it spread into the air (the aerosolization) after flushing. Using two different types of toilets commonly used in hospitals, the researchers found C. difficile in the air 25 cm above the toilet seat and determined that surface contamination with this bacteria occurred within 90 minutes after flushing, meaning that droplets are suspended in the air for some time before settling on a surface. The recent study is particularly concerning because the C. difficile bacterium has a high survival rate and it is not uncommon for sufferers to experience explosive diarrhea, making possible bathroom contamination more likely.

Previous research has demonstrated how flushing domestic and hospital toilets without a lid can also contaminate the surrounding surfaces with other types of bacteria, such as E. coli. The researchers of the current study recommend thorough hand-washing after toilet use, frequent bathroom cleaning, and the implementation of newer toilets that do not have an aerosol effect when flushed, especially in healthcare facilities.

Paper Towel or Air Dry?

Canadian researchers recently evaluated the bacterial content found on unused paper towels. In their pilot study, published in the American Journal of Infection Control,2 the research team tested six brands of commercially available paper towel products in Canada. Similar to previous studies, paper towels made from recycled materials contained significantly more bacteria than that made from new pulp. The concentration of bacteria in recycled paper was 100-1,000 times greater than that of virgin wood pulp brands. The researchers are especially concerned about the presence of the toxic Bacillus bacteria, which is associated with food borne and other illnesses. The Bacillus genus of bacteria has both good and bad strains and can sometimes survive even bleach disinfection processes, which are common in paper mills.

Although the bacterial content transmitted to the study participants’ hands during drying with paper towel was very low for all of the tested brands, those who air-dried their hands had almost no bacteria on them after washing. The researchers say that this study does not suggest that paper towels are necessarily unsafe, but that immunocompromised and other vulnerable individuals may wish to take particular caution.


It’s important to understand that germs (microorganisms) are everywhere. Our bellybuttons alone are host to an entire community of bacteria, and this in itself is not a bad thing. What we should focus on is preventing the spread of illness-causing bacteria, viruses, and fungi. Health Canada recommends frequent, proper hand washing, using regular soap and water and, sometimes, the use of an alcohol-based hand sanitizer.3 They do not recommend anti-bacterial soaps because these products destroy good bacteria as well as bad and can add to the current problem of antibiotic-resistant bacteria. You should wash your hands for a full 15 seconds, ensuring that you reach all parts of your hands, as friction is an important part of removing contaminants. Rinse well under warm running water, using a rubbing motion.

Although the study above on paper towels may discourage you from using them, keep in mind that other surfaces, such as sink taps, soap dispensers, and door handles, are likely to harbour far more bacteria than a new piece of paper towel. At home, wash kitchen and bathroom surfaces regularly and, when using public restrooms, minimize hand contact with surfaces and consider air-drying your hand when you have the option available.

First published in the Inside Tract® newsletter issue 182 – 2012
1. Best et al. Potential for aerosolizaton of Clostridium difficile after flushing toilets: the role of toilet lids in reducing environmental contamination risk. Journal of Hospital Infection. 2012;80:1-5.
2. McCuskey GendronL et al. Evaluation of bacterial contaminants found on unused paper towels and possible postcontamination after handwashing: A Pilot Study. American Journal of Infection Control. 2011;E1-e5.
3. Health Canada. It’s Your Health – The Benefit of Hand Washing. Available at http://www.hc-sc.gc.ca/hl-vs/iyh-vsv/diseases-maladies/hands-mains-eng.php. Accessed 2012-01-11.
Image: volodymyrshtun | bigstockphoto.com