A study reported in the American Society for Microbiology in 2015, finds that we could be in for a bit of a surprise when we visit even the cleanest of public restrooms. The researchers in this study found that even just cleaned restrooms often house an invisible 'microbial zoo,' which starts developing minutes after cleaning.
Here's how they came to this conclusion. The researchers selected four restrooms at San Diego State University. Two women's restrooms, one that was quite busy and the other not so active, as well as two men's restrooms, also one busy and the other not so.
The restrooms were thoroughly cleaned with a bleach cleaning solution. Bleach tends to be used sparingly today in the professional cleaning industry. This is because it can have determinantal impacts on the user and the environment, especially if used improperly. However, there is no question that bleach is a highly effective disinfectant, and kills many forms of bacteria, as well as viruses associated with the flu and the common cold.
Once the researchers had cleaned the restrooms with the bleach cleaning solution, the following surfaces were analyzed: toilet seats, the floor area in front of the toilets, and the soap dispenser pump. The scientists swabbed these areas gathering microbial samples. They even used what is called 'genetic sequencing technology,' which detects microscopic organisms that don't grow in Petri dishes, all on the lookout for little germs, viruses, and bacteria on these surfaces.
Here's what they found:
• Directly after cleaning, there were few pathogens on these restroom surfaces. However, within one hour, all four restrooms were recolonized with microbes, some health-risking.
• Fecal bacteria was detected on toilet seats as well as on hand-operated soap dispensers.
• Altogether, 77,000 distinct traces of bacteria were uncovered; while some were dead or dormant, many others were alive and healthy, having the potential to spread disease.
• The different types of bacteria did not grow at the same rates; some developed faster, others slower.
• After five hours, the one form of bacteria that was found in all four restrooms in 'overwhelming abundance' was Staphylococcus.
Staphylococcus causes staph infections of various types. While they can be irritating, for instance, if they develop in the nose or ears, they typically can be treated with over-the-counter skin antibiotics. But if staph infections get into the bloodstream, they can be serious. We should note that MRSA, which is resistant to most antibiotics, is a form of a staph infection. However, in this study, no MRSA was detected in the restrooms.
The researchers continued to test the restrooms, taking bacteria counts for eight weeks. During that time, they found that even after repeated cleanings, the same patterns were repeated. After about an hour, the microbial zoo in the restrooms started rebuilding.
The study did not specify why the microbial zoo returned so quickly. It actually could be the result of the ways these restrooms were cleaned. Traditional spray-and-wipe and floor mopping methods tend to spread germs as they are used. This is why many administrators and cleaning professionals have turned to cleaning alternatives, such as no-touch cleaning systems that remove – not spread – germs and bacteria.
By the way, this study was funded by the Alfred P. Sloan Foundation's Microbiology of the Built Environment Program, along with resources provided by the University of Chicago Research Computing Center.
In other words, it was not funded by any organization looking for a particular outcome. The goal of the study, as Dragnet's Sergeant Joe Friday would say, was 'just the facts, ma'am.'
Robert Kravitz is a former building service contractor, having owned, operated, and then sold three contract cleaning companies in Northern California.
He is the author of two books about the industry and continues to be a frequent writer for the industry.
Robert is now president of AlturaSolutions Communications, which provides communications and marketing services for organizations in the professional cleaning and building industries.