UNITED STATES--You may already be on high germ alert in public restrooms, but it turns out there are some other areas you may not be thinking about that are major contamination concerns.

A new study by Kimberly Clark found gas pumps and mailbox handles may be among the dirtiest surfaces we touch. Trained hygienists tested surfaces in six cities and found 71 percent of gas pump handles had high levels of contamination.

Mailbox handles, escalator rails and ATM buttons were also germ cities. Researchers say the study is more proof of how important it is to wash your hands.