Top 7 Dirtiest Surfaces

Did someone say cold and flu season? Just as sniffling and sneezing is beginning to invade schools and offices across the land, a new series of tests in six major U.S. cities reveals the dirtiest surfaces Americans touch. The results, released by Kimberly-Clark Professional, show which surfaces are most likely to be highly contaminated, potentially exposing people to illness-causing bacteria.

The testing was conducted by hygienists in busy locations in Atlanta, Chicago, Dallas, Los Angeles, Miami and Philadelphia. Using a device commonly used to monitor sanitary conditions in industry, hygienists tested the objects to measure levels of Adenosine Triphosphate (ATP). Everyday objects with an ATP reading of 300 or higher are considered to have a high risk for illness transmission. In all, more than 350 separate swabs were taken and analyzed.

The percentage of public surfaces tested and found to have high levels of contamination (an ATP count of 300 or higher), includes:


7. Vending Machine Buttons
35 percent of all vending machine buttons tested positive for ATP levels of 300 or higher. Dr. Charles Gerba, Professor of Microbiology at the University of Arizona, said, “This new testing is compelling because it underscores the importance of hand and surface hygiene. Most cold and flu viruses are spread because people touch surfaces in their immediate area and then touch their faces, other objects and other people. Washing and drying your hands frequently throughout the day, can help prevent your risk of getting sick or spreading illness around the office.”


6. Crosswalk Buttons
Tying with vending machine buttons are crosswalk buttons, of which 35 percent of tested positive for high levels of ATP.

5. Parking Meters/Kiosks
40 percent of parking meters and parking kiosks tested positive for ATP levels of 300 or greater. And if you’re parking your car to go grocery shopping, remember that the handles of almost two-thirds of the shopping carts tested in a 2007 study at the University of Arizona were contaminated with fecal bacteria. In fact, the bacterial counts of the carts exceeded those of the average public restroom

4. ATM Buttons
If you’re touching money, you’ll probably wach your hands anyway, especially now that you know that 41 percent of ATM machine buttons tested high for ATP. ”The likelihood for illnesses to transfer from the objects that people use every day like ATMs and parking meters is eye-opening,” said Brad Reynolds, North American Platform Leader, The Healthy Workplace Project, Kimberly-Clark Professional.

3. Escalator Rails
43 percent of escalator rails showed evidence of high levels of ATP. Yikes.

2. Mailbox Handles
Where you’d least expect it, 68 percent of mailbox handles that were tested came up positive for ATP levels of 300 or higher.

1. Gas Pump Handles
71 percent of gas pump handles (gas pump handles!) tested positive for high levels of ATP.

According the Centers for Disease Control and Prevention (CDC), handwashing is the best way to prevent infection and illness. Here’s how to wash your hands most effectively:

Wet your hands with clean running water and apply soap. Use warm water if it is available.

Rub hands together to make a lather and scrub all surfaces.

Continue rubbing hands for 15-20 seconds.

Rinse hands well under running water.

When out, dry your hands using a paper towel or air dryer. If possible, use your paper towel to turn off the faucet.

Always use soap and water if your hands are visibly dirty.

If soap and clean water are not available, use an alcohol-based hand rub to clean your hands.