The world is dirty. Everywhere we go, there are germs. Our phones, bus seats, door knobs, park benches, and other surfaces harbor bacteria, fungus, and viruses. When we shake hands or sit in the same row on an aircraft, we transfer these microscopic organisms to one another.
Researchers are now discovering that we spread our microorganisms via our financial transactions. Each dollar that is given from person to person, whether it is through tip jars, vending machines, or the meter maid, tastes a small portion of the environment from where it originates before moving on to the next recipient and subsequent location.
DNA from our pets, drug residue, and pathogenic bacteria and viruses are among the items that have been discovered on our currency. The results show how money can secretly record human activity, leaving behind what are referred to as “molecular echoes.”
Paper money is dirty. And you might never want to touch it again once you realize what it hides on its surface.
What Money Is Made Of
Like all infants, brand-new bills start out pure and unblemished. In fact, Crane Curreny’s stock paper isn’t even made of paper. Paper is created from wood pulp, whereas money is a mixture of 25% linen and 75% cotton, with red and blue fibers strewn about to deter forgery. Then, depending on the denomination, sheets are printed using various inks: black on the front, green on the reverse, and metallic and color-shifting ink on other places. The finished sheets are then cut into currency size using guillotine cutters. Shrink-wrapped bricks of 4,000 notes are shipped to Federal Reserve institutions and other places. 38 million banknotes are printed each day at the two printing facilities in Fort Worth, Texas, and Washington, DC. These bills all venture out into the world to experience their own adventures.
What’s On A Dollar Bill?
A study conducted in 2017 discovered more than a hundred distinct bacterial strains on $1 banknotes in circulation in New York City. Propionibacterium acnes, a bacteria known to cause acne, and Streptococcus oralis, a typical bacteria present in our mouths, were among of the most frequent bugs on our bills.
The research team at New York University, lead by biologist Jane Carlton, also found traces of DNA from domestic animals and from particular bacteria that are only found in certain meals.
A related study found DNA traces on ATM keypads that represented the types of foods people in various communities ate. The consumption of domestic chicken in central Harlem was higher than that of bony fish and mollusc species in Flushing and Chinatown. People’s food transfers from their fingertips to touchscreens, allowing researchers to partially reconstruct their most recent meals.
We don’t just leave food behind. Almost 80% of US dollar bills contain traces of cocaine. Although less frequently than cocaine, other narcotics such as morphine, heroin, methamphetamine, and amphetamine can also be seen on bills.
It may not seem very useful to identify the drugs or meals people consume based on their financial relationships, but scientists are using this kind of information to comprehend disease trends. The majority of the microorganisms that the New York researchers discovered do not spread illness. However, other research has revealed that disease-causing bacterial or viral strains might travel with our money.
Salmonella and a deadly type of E. coli are only two examples of the bacteria that may live on pennies, nickels, and dimes and can hide out on ATMs. The extent to which other bacteria, such the skin-infection-causing methicillin-resistant Staphylococcus aureus (MRSA), could transmit illnesses is unknown, but it has been identified on Canadian and American banknotes.
Despite our best efforts, germs follow us and are carried by us. The good news is that the majority of exposures don’t make us ill, even though disease-causing microorganisms can live in locations like ATMs.
Money Laundering
Rarely does a disease spread through the exchange of money, and no significant illness outbreaks have originated from our ATMs. We could make our money cleaner even though it doesn’t appear frequent for viruses to spread through money.
The best approach to clean money in between transactions is still being researched. Older banknotes can be cleaned of oils and dirt from human fingers by running them through a machine that exposes them to carbon dioxide at a precise temperature and pressure. The heat also destroys bacteria that would otherwise persist on the bills.
Despite having a greater rate of bacterial development than plastic polymers, the fabric used to make U.S. currency is still a combination of cotton and linen. Many nations are switching from paper money made of natural fibers to plastic money, which may be less bacterially friendly. Plastic money has been available in Canada and the UK since 2013, last year switched to bank notes made of plastic.
The travel history of the dollar can be used to track how we transmit disease in other ways even if our money isn’t directly to blame for doing so. Users of the 1998-founded website WheresGeorge.com can track dollar bills by noting their serial numbers. WheresGeorge has documented the geographic locations of banknotes totaling more than a billion dollars in the nearly 20 years since the site’s inception.
In order to track outbreaks, scientists at the Max Planck Institute and University of California, Santa Barbara are now using information from the WheresGeorge website. Even the spread of the 2009 swine flu was forecast using data from WheresGeorge on human movement and interaction rates.
Even though we don’t know how much money contributes to the spread of diseases, it’s probably best to follow mom’s advice when handling cash: wash your hands and avoid putting it in your mouth.