Drugs, DNA And Disease Discovered On Our Dollar Bills
April 24, 2014

Drugs, DNA And Disease Discovered On Our Dollar Bills

Lawrence LeBlond for redOrbit.com - Your Universe Online

With as much money that is being exchanged on a daily basis it may concern most people to know that they are not only transferring paper from one hand to the next, but potentially thousands of microbes along with it.

Researchers from New York University’s Center for Genomics and Systems Biology have found that those greenbacks in our wallets do not only contain trace amounts of cocaine and other drugs, as has been previously reported, but each bill may carry as many as 3,000 types of bacteria. While most of these may be harmless, some bills have been discovered to carry DNA from drug-resistant microbes and traces of anthrax and diphtheria.

What’s more, the study authors, led by NYU Department of Biology’s Jane Carlton, found microbes on the money that matched those found in human mouths and even in female genitals. She posits that currency could be one way that antibiotic-resistant genes move around cities.

The study, called the Dirty Money Project, offers an in-depth look at the organisms that thrive on our cash. One of the project’s goals is to provide information that could help health workers catch disease outbreaks in NYC before they can spread.

"We're not trying to be fear mongers, or suggest that everyone goes out and microwave their money," Carlton said in an interview with NPR Shots’ Michaeleen Doucleff. "But I must admit that some of the $1 bills in New York City are really nasty."

For the study, Carlton and her colleagues analyzed dollar bills taken from Manhattan Bank. They have sequenced all the DNA found on 80 bills from the bank. The most common microbes found on the bills are ones that cause acne. The team also found a lot of skin bacteria that aren’t pathogenic, meaning they are harmless to human health. Some of these microbes may even protect the skin from other more harmful bacteria, Carlton explained.

Carlton said that, not surprisingly, many mouth-based microbes were found on the bills – largely because people tend to lick their fingers when they count money. Also, they found bacteria that thrive in the vagina, suggesting that “people probably aren’t washing their hands after the bathroom.”

As for the trace amounts of anthrax, Carlton told NPR there is no cause for alarm.

"Anthrax is a very common bacteria in soil," Carlton says. "People who work with soil, like farmers, are often exposed to it. It's only when anthrax is weaponized and sent through the mail that it causes those issues."

Despite the overwhelming amount of microbes found on our cash, it shouldn’t be too much of a concern for people.

“Microbes are so important, are very ubiquitous and they surround us all the time,” Carlton told ABC News. “We did find certain microbes that we might be a little concerned about, but that doesn’t mean that people should be unduly concerned.”

The study also picked up genes in the cash that make bacteria impervious to antibiotics, including penicillin and methicillin, turning some bacteria into dangerous pathogens.

"Now we know that viable bacteria are on money and could serve as a mode of transmission for antibiotic-resistant genes," Carlton noted. "Money is a frequent route of contact between people in New York City."

It is still unclear how significant money is in the transmission of pathogens and adding fuel to the fire when it comes to disease outbreaks.

Some have discussed changing the material used for currency to help keep dangerous bacteria at bay. But there is no evidence yet if that would make for safer money.

Canada recently started printing money on flexible sheets of polymer film – basically a fancy plastic. Another country that has started printing plastic money found that less bacteria is found on these polymer-based bills than on traditional cotton-based currency.

A study reported last week in the Wall Street Journal, however, found that microbes live far longer on plastic money.

The NYU study found that the most common bacteria living on our cash include Staphylococcus aureus, Escherichia coli, Helicobacter pylori and Corynebacterium diphtheriae.

While it is unlikely that all bacteria can be removed from our bills, the best way to protect against money’s microbial jungle is to simply wash your hands after handling cash.

As of this writing, Carlton's study is yet to be published.