Up to 3000 different bacteria live on paper money

In a research project to identify DNA on paper money at New York University, the researchers found that currencies are the refuge of hundreds of different types of bacteria. This is the means of "transporting" bacteria from one hand to another and is a source of many dangerous diseases to human health.

Through the material analysis of the $ 1 bill, the researchers discovered more than 3000 different types of bacteria. This number far exceeds all previous studies when screening a tissue under a microscope to detect bacteria. However, the researchers only identified the DNA of about 20% of the bacteria. The rest is not listed in the genetic data bank.

Among the strains of bacteria present on paper money, the most common is the type that causes acne. Some other bacteria are equally dangerous to cause stomach ulcers, pneumonia, food poisoning and staph infections in humans. Some types of bacteria on paper money also contain genes that can cause the decline of human resistance.

Jane Carlton, director of the Center for Molecular Biological Studies at New York University, said: "We were really surprised by what we found. We even found bacteria growing. on paper money ".

Another unpublished study has also provided a view of the dirty level of paper money . From rubles to euros, paper money is one of the most circulating vehicles in the world. For a long time, epidemiologists have been concerned that paper money is a source of disease spread that is difficult to control.

Philippe Etienne, director of Innovia Security Pty, who conducted a study on 23 types of banknotes from many different countries, said: "The wallet you put on your body carries the temperature of your body. This is the key. is a petri dish that nourishes the most perfect bacteria ".

According to US central bank statistics, an additional US $ 150 billion is added annually worldwide. Each 1-dollar note is printed on cotton mixed with flax and can be used for at least 21 months. In 2014 alone, the US Federal Reserve spent $ 826.7 million to print a total of $ 297.1 billion in total value.

People also contribute a significant part in the development of bacteria on paper money.

To make paper money more sustainable, some countries like Canada or Bhutan have used polymer materials to print money with biological identification elements to increase the level of anti-counterfeiting.

In a study of the impact of money printing materials on public health, researchers at the University of Ballarat, Australia examined the changes of 10 types of paper money during travel from supermarkets, cafes to restaurants. The study was conducted in 10 countries with the types of banknotes circulating there.

According to research conducted in 2010 by the food safety and pathogen magazine, there are differences in the level of bacteria on paper money in different countries. Besides, the study also showed that bacteria on polymer money are less than cotton paper money."Pre-printed with polymer materials is characterized by not being water repellent. This is a feature that helps it contain less bacteria than cotton money."

In another study conducted by the Center for Research on Antibiotic and Infection Control, scientists tested bacterial cultures in 7 different currencies. Research results show that there are still some types of bacteria that can survive for a long time on polymer foil.

People also contribute a significant part in the development of bacteria on paper money. Bacteria can eat mucus or residue on human skin during the process of paper money being passed from one person to another.

Nabil Lawandy, a physicist at Brown University, who designed paper-based security for more than 19 central banks, said: "When you hold a note, you're offering food for those types of bacteria on it ".

In a paper surface study carried out by a team of scientists from India, the Netherlands and the United States, the researchers isolated 93 types of bacteria on the surface of paper money. In 2012, microbiologists at Queen Mary University, London, concluded that 6% of paper money circulating in the UK is containing E. coli at a level similar to a toilet seat.

In the latest study conducted by the New York University team, researchers used DNA data banks and computer analysis to quickly identify the DNA of different types of bacteria. present on paper money. Therefore, the study found more bacteria than previous studies that only observed paper money under a microscope.

In the experiment, the researchers analyzed DNA samples on 80 sheets of paper worth $ 1 collected from a bank in Manhattan. The collected results are 1.2 billion. These data account for 320GB of computer storage, equivalent to the amount used to store all medical documents at a library.

Half of the 1.2 billion pieces of DNA collected are human. The other half belongs to bacteria, viruses, fungi and other biological pathogens. In addition, the researchers found a small amount of the virus that causes anthrax and diphtheria. Besides, on research bills, there are also DNA of horses, dogs and also rhinos.

Genome researcher at New York University, Julia Maritz, who has done a lot of DNA analysis, said: "We have discovered many species of organisms on a single sheet of paper."