Cite this article

NIDA. (2014, November 6). Dirty Money: How Cocaine and Germs Contaminate Our Cash. Retrieved from

press ctrl+c to copy
The NIDA Blog Team
November 6 2014

Q: What do cocaine and bacteria have in common?

A: They both contaminate our cash.

While most of the dollar bills you come into contact with would test positive for cocaine, that doesn’t mean that they were used to snort cocaine. In fact, less than 1 percent of people age 12 or older even use the drug.  

It happens because cocaine is a very fine powder that easily transfers from bill to bill. One bill with cocaine on it can contaminate an entire cash drawer or ATM. It’s a little like someone with a cold—if he or she sneezes on you, the chances are good that you’ll catch what the individual has.

But don’t worry. Your stash of cash has only a tiny amount of cocaine on it—not enough to get you high or cause you to fail a drug test.

And What About Bacteria?

Well, germaphobes beware—researchers from New York University found hundreds of different bacteria on dollar bills. In all, they identified over 3,000 different types of bacteria that caused pneumonia, food poisoning, and staph infections. 

Want To Know What’s in Your Pocket?

Where’s George? allows users to enter and track dollar bills. It shows how far money can travel while it is in circulation. 

So, the bottom line here is that money is dirty. And while cocaine is not likely to get on your skin from handling money, germs will. So, we suggest washing your hands frequently.