Just How Dirty are Public Restrooms?

istock / istock

Some people feel so terrified of the germs lurking in public bathrooms that they practically cover the entire stall in paper before they go. Others try holding it to avoid germ-infested public toilets. Good news germaphobes! A new study finds that public bathrooms contain no more germs than our own bathrooms. 

To understand the bathroom environment, researchers examined the microbial makeup of the floors, toilet seats, and soap dispensers at four different restrooms—two female and two male—at San Diego State University. First, the brave researchers cleaned the bathrooms; then they took samples from the various surfaces, first hourly and then daily for eight weeks. They analyzed the various germs found in each area. Unsurprisingly, they discovered that fecal bacteria flooded the bathrooms first.

"When you flush the toilet it goes airborne and spreads these viruses throughout the bathroom," Michael Schmidt, professor and vice chair of the department of microbiology and immunology at the Medical University of South Carolina, told HealthDay. (Watching this video is not for the faint of heart.)

The cool, dry, oxygen-rich public bathroom turns out to be terrible at fostering bacterial growth, and fecal bacteria quickly die, accounting only for 15 percent of the germs in a public toilet. However, bacteria that thrive on skin tend to weather hostile environments better and these make up the majority of bacteria discovered in the WC.

"You're constantly turning over this skin that's literally covered in microbes," Schmidt explained.

Skin bacteria along with outdoor bacteria made up the majority, 68 percent, of the potty microbes. The researchers most commonly found Staphylococcus, a genus of gram-positive bacteria that reside on skin and mucous membranes. Most Staphylococcus remains harmless, though Methicillin-resistant Staphylococcus aureus, MRSA, can cause nasty infections and resists antibiotic treatment. The researchers also noticed a few viruses, such as human papillomavirus and herpes, but overall there were more bacteria than viruses in the loo.

But there’s more good news. Five hours after cleaning, the bacteria population establishes itself and it stays relatively stable, even after many, many uses.

But that still doesn’t mean it’s cool to skip a good hand washing:

“If you do not want to become colonized with someone else's stuff, you need to wash your hands to inactivate the microbes you've picked up," Schmidt said. "Hand sanitation is the human being's best way of protecting ourselves against diseases."

So go ahead, sit down on that public toilet seat. Just skip the hand dryer.