Hand washing study reveals dirty surprises

Kathleen Blanchard's picture
Study finds 95 percent of people don't wash their hands after using the bathroom

How would you feel the next time you shake hands with someone if you knew that only 5 percent of people washed their hands properly after using the bathroom? University of Michigan researchers studied hand washing to discover some nasty surprises. It seems proper hand washing may be a lost art.

In the new study, researchers found 33 percent of people who do wash after going potty fail to use soap and 10 percent do not even wash their hands at all.

The study finding that appears in the Journal of Environmental Health is based on hand washing habits observed in 3,749 people in public restrooms.

Investigators for the study found men are the worst offenders when it comes to doing it properly with 20 seconds of vigorous hand washing that includes water plus soap.

Most people wash their hands for about 6 seconds, the researchers discovered.

Carl Borchgrevink, associate professor of hospitality business and lead investigator on the study said the finding was a surprise because there has been research suggesting proper hand washing is on the rise.

Public health messages during flu and cold season have indeed sent the message that hand washing as the single most effective way to stop the spread of infection.

Consider recent stories in the news about tainted food from E.coli and other germs that have sickened large numbers of people.


A 2011 study found cell phones contain fecal germs. In the study, 92 percent of cell phones in the UK tested were found to have E.coli – that lives in our intestines.

The suspicion is either people are texting in the bathroom or simply not practicing good hand washing, lending support to the current study.

Another study in 2011 found shopping carts are full of E.coli, prompting most grocery stores to offer anti-bacterial wipes when you enter the store.

Borchgrevink used to be a chef and restaurant manager before he became a researcher.

“Imagine you’re a business owner and people come to your establishment and get foodborne illness through the fecal-oral route – because people didn’t wash their hands – and then your reputation is on the line,” he said. “You could lose your business.”

Fifty percent of food borne illness comes from improper hand washing. E. coli spreads from hand to mouth contact. All it takes is a slightly compromised immune system that can happen to normally healthy people, the very young and older adults to cause illness. E. coli can also be ingested on food. The most common way it is spread if from person to person.

Key findings from the study include:

  • Signs help people remember to wash their hands
  • Hand washing becomes less important as the day goes on. People who were out for dinner and drinks were less likely to wash up after going to the bathroom.
  • Dirty sinks turn people away from washing their hands at all
  • Women wash their hands after the potty more than men – 78 percent of women do it, but only 50 percent of men wash up.
  • Just 7 percent of women, compared to 17 percent of men do not wash their hands at all after going to the bathroom.

If you're not sure how to do it, follow the CDC's guidelines, outlined here.

The study highlights the fact that we may be spreading infection by ignoring our mother’s guidance to wash our hands after going to the bathroom – something the finding showed only 5 percent of people seem to be doing properly.

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