Like HowStuffWorks on Facebook!

10 'Harmless' Things You Should Really Wash Your Hands After Touching

Communal Pen
Keep that pen, Mr. Messenger. We'll use our own. Jupiterimages/
Keep that pen, Mr. Messenger. We'll use our own. Jupiterimages/

They say the pen is mightier than the sword, and thanks to Dr. J. Owen Hendley, a professor of pediatrics at the University of Virginia, we now have another reason to believe it's true. In 2006, Hendley co-authored a study investigating the prevalence of rhinoviruses -- the germs responsible for the common cold -- in hotel rooms. Here's what Hendley and his team did: They asked 15 people with confirmed colds to spend the night in a nearby hotel. After the sniffling, sneezing guests checked out, scientists entered the rooms before the cleaning staff and tested various surfaces for the presence of rhinoviruses. As you might expect, they found virus particles on door handles, TV remotes, light switches, phones and alarm clocks. But they also found a large number on hotel pens [source: Associated Press].

By extrapolation, it's safe to assume that other communal pens -- at banks, grocery stores, day-care centers, restaurants and department stores -- are just as infected. In fact Dr. Neil Schachter, a pulmonary disease specialist at Mount Sinai Hospital, recommends that you should carry your own pen at all times and "use it instead of the doctor's, the delivery guy's or the restaurant waiter's" [source: Prevention].