dollar bill closeup

Dollar bills are swarming with acne-causing bacteria

Add this to the list of the advantages of going to an all-digital, cashless society. The WSJ reports that researchers from NYU’s Dirty Money Project (real name) analyzed American bank notes for micro-organisms and genetic material and found over 3,000 types of bacteria, including some pretty nasty stuff:

Easily the most abundant species they found is one that causes acne. Others were linked to gastric ulcers, pneumonia, food poisoning and staph infections, the scientists said. Some carried genes responsible for antibiotic resistance.

Turns out the conditions paper money are kept under are perfect for breeding microbes: wallets are generally kept near body temperature, with regular human contact that adds skin oil and sweat, and frequent transfer among humans.

American currency is printed on a cotton-linen blend, while many other countries around the world have moved to a longer-lasting plastic polymer film. One Australian study found the non-absorbant polymer notes hold fewer bacteria, but another study showed some germs actually last longer on the new notes.

Tyler Cowen adds a historical footnote: “This [health concern] was… a relatively frequent complaint in 19th century monetary writings, with the advent of banknotes.”

Photo: Corey Holms