Bacteria Infects Thousands of Your Dollars

Researchers have discovered that thousands of bacteria live on the cash you carry around with you. In the first comprehensive study of the DNA on dollar bills, researchers at New York University found that currency is a medium of exchange for hundreds of different kinds of bacteria as bank notes pass from hand to hand. By analyzing genetic material on $1 bills, the NYU researchers identified 3,000 types of bacteria in all—many times more than in previous studies that examined samples under a microscope. Even so, they could identify only about 20 percent of the non-human DNA they found because so many microorganisms haven't yet been cataloged in genetic data banks. One cause appears to be acne. Others were linked to gastric ulcers, pneumonia, food poisoning and staph infections. "It was quite amazing to us," said Jane Carlton, director of genome sequencing at the Center for Genomics and Systems Biology."We actually found that microbes grow on money."

Paper money is one of the most frequently passed items in the world. Hygienists have long worried that it could become a source of contagion. "A body-temperature wallet is a petri dish," said Philippe Etienne, managing director of Innovia Security Pty. Ltd., which makes special bank-note paper for 23 countries. Central banks and state treasuries usually worry more about counterfeiting and durability than microbiology, currency experts say. Talk about dirty money. Yecch!