Remember when you saved your change and rolled it into those little paper tubes as a kid? When you were done, your hands were filthy, and that musty smell stuck to them long after you washed them. Well, that brown and grey gunk was more than just dirt.

Studies have shown that there are more germs on a piece of money than there are on a toilet seat. The average bill houses over 20,000 different kinds of bacteria and can carry a live flu virus for up to two weeks, infecting shoppers and savers alike along the way.

Germs aren’t all you’ll find if you study a nice, ripe twenty. They’re covered in DNA and skin cells, and they are also, more often than not, laced with drugs like cocaine, PCP, and methamphetamine.

One dollar bills are decidedly the most teeming, and a wallet, which is usually kept around body-temperature, is a microbial dream house.

This isn’t exactly breaking news. We’ve been told this time and again, but even though we’ve built a cultural taboo around hand washing in the bathroom, we still keep on hanging onto our cash with our bare hands without a second thought.

Mastercard released a study in 2014 showing that out of 9,000 consumers from all around Europe, the majority of people know that their cash is gross but don’t do anything about it. Why? Psychologists say that because money is across the board a good thing – a source of power, stability, and wealth, it’s hard for people to see it in a negative light. We don’t want to spoil the spoils by connecting the bad (disease) with the good (riches).

On a more practical note, treasuries both national and state-level are far more focused on preventing and investigating counterfeiting than about disinfecting the genuine article.

So please, for the love of George Washington – never, EVER put your money where your mouth is.