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Dirty Money: Researchers Find Bacteria Living on Cash


Mo' money, mo' problems.

Paper money carries thousands of different types of bacteria and actually has the ability to grow microbes, according to a recent study. That means when you reach into your wallet to pay for that latte, chances are you are touching a virtual petri dish of germs.

Researchers at New York University's Dirty Money Project analyzed genetic material on $1 bills and identified 3,000 kinds of bacteria. The most abundant type they found causes acne, while other strains can lead to illnesses such as pneumonia, food poisoning and staph infections.

Consider that the average dollar bill, printed on a cotton-linen blend, has a life cycle of 21 months. How many times that bill is passed from person to person in 21 months is hard to quantify, but we do know money is one of the most frequently passed items worldwide.

Still, many people don't think of money as dirty.

Scott T. Youngquist, MD, an associate professor of emergency medicine at the University of Utah School of Medicine, says it's about time we did. "Money is no different than any other public item that the rest of the unwashed populace touches: a bus handrail, a toilet trip lever, a park bench," he explains. "Only, no one ever washes money, unless you count money laundering."

According to Youngquist, "Unless your 'Benji' came straight from the mint, it's going to be covered with germs."

But he doesn't want people to worry too much. It's unlikely money will make you sick, he says. Following these tips will help protect you just in case:

  • Wash your hands or use hand sanitizer after handling money.
  • Use a debit card instead of cash whenever possible.
  • Don't lick your fingers to count bills.