Jane Carlton, head of the Dirty Money Project at NYU, hopes to follow the spread of diseases in NYC by keeping track of the microscopic organisms making a home in our wallets. Carlton’s team examined the DNA found on 80 $1 bills from a local bank, and discovered 3000 types of bacteria, including strains responsible for acne, pneumonia, and food poisoning. “Some of the $1 bills in New York City are really nasty,” says Carlton, who also found the bills contained bacteria common to the mouth and the vagina. One might blame the strip club, but Carlton thinks “people probably aren’t washing their hands after the bathroom.”
In addition to bacteria and fungi, researchers also found human DNA, along with the DNA of dogs, horses, and even a white rhino. Carlton also discovered genes which can make bacteria immune to antibiotics, raising a fear that cash “could serve as a mode of transmission for antibiotic-resistant genes.” Plastic-based bills like the ones used in Canada have been considered as an alternative to paper money, but studies found that while less bacteria grows on plastic bills, the bacteria may live longer.