13.1 billion cash payments were made in the UK in 2017, but paying for goods with cash is declining, with only 22% of transactions being paid for with coins and notes.

Shoppers like the convenience of contactless card payments, but could paying by plastic benefit your health too?

Key findings

Testing your cash

Microbiologists studied the bacteria in a controlled lab environment over a period of 8 weeks.

  • 19 different types of bacteria discovered

  • 2 superbugs including MRSA discovered on our coins and notes

  • Listeria found on 20p, 50p, and 1 coins and on our notes

Money under the microscope

Dr Paul Matewele, Professor of Microbiology at London Met, and his students took 36 samples from a random selection of all denominations of coins and notes.

19 different bacteria were found across UK coins, polymer 5 and 10 notes and paper 20 and 50 notes.

This includes 2 life threatening bacteria associated with antibiotic resistant superbugs: Staphylococcus aureus (MRSA) and Enterococcus faecium (VRE).

The life-threatening airborne bacteria, Listeria was also found.

The results in full

The study revealed cash is incredibly dirty and a breeding ground for bacteria.

Last year the World Health Organisation (WHO) published its first ever list of antibiotic-resistant bacteria, which pose the greatest threat to human health.

Shockingly two of these bacteria were found on the cash we touch everyday.

Bacteria on our coins

1pBacillus, Coliforms & Micrococcus
2pBacillus, Bacillus amyloliquefaciens, Coliforms, Enterococcus & S. Aureus
5pBacillus Amyloliquefaciens, Coliforms, Enterococcus, Micrococcus & S. Aureus
10pColiforms, Enterococcus, Micrococcus & S. Aureus
20pBacilus firmus, Bacilus lentus, Listeria & Micrococcus
50pAneurinibacillus Aneurinilyticus, Brevibacillus Centrosporus, Coliforms, Micrococcus & Listeria
1B. lentus, B. Pumilus, Coliforms, Listeria & S. Aureus
2Bacilus Pumilus, Geobacillus Thermoglucosidasius & S.aureus

Bacteria on our bank notes

5Bacillus Pumilus, Coliforms, Listeria & Yeast
10Enterococcus, Listeria, Micrococcus & S. Aureus
20Bacillus, Coliforms, S. Aureus
50Bacillus, Micrococcus & S. aureus

Some of the most common bacteria were:

  • Staphyloccus Aureus (MRSA): The 2p, 5p, 10p, 1 and 2 coins, and the 10, 20 and 50 notes were all found to have Staphyloccus Aureus (MRSA). This antibiotic resistant bacteria is listed as one of the greatest threats to life by the WHO. It can cause boils, impetigo, food poisoning, cellulitis and toxic shock syndrome.

  • Enterococcus faecium: Found on the 2p, 5p and 10p coins as well as the 10 note. It is also present on the World Health Organisation's list of antibiotic resistant bacteria. It can cause infections of the abdomen, skin, urinary tract and blood. People with lowered immune systems are particularly susceptible to this infection.

  • Listeria: Found on the 20p, 50p and 1, as well as the 5, 10 and 20 notes. The bacteria can lead to infection which is usually caught by eating contaminated food. The infection can cause food poisoning and even miscarriage. There have been 47 cases of Listeria reported as of June 2018 and 9 deaths.

  • Bacteria found in faeces: This can cause urinary tract infections and septicemia. Bacteria which can cause thrush, nappy rash and diarrhoea was also found.

What the experts say

One of the most shocking discoveries was finding so many microorganisms thriving on metal, an element you wouldn't normally expect to see germs surviving on. The bugs have adapted to their environment, resulting in coins becoming a breeding ground for harmful bacteria.

People who have compromised immune systems could be most at risk from handling dirty money - if you're visiting people in hospital who might be vulnerable to infection, you could unknowingly transfer bacteria off your cash which is resistant to antibiotics.

Source: Dr Paul Matewele, Professor of Microbiology at London Metropolitan University

We were really shocked when the results revealed two of the world's most dangerous bacteria were on the money we tested.

We thought the new polymer notes would be cleaner but were stunned to find out even they were growing some life threatening bugs. These findings could reinforce the argument for moving towards a cashless society and might be the nail in the coffin for our filthy coppers. I suspect people may think twice before choosing to pay with cash knowing they could be handed back change laced with superbugs.

We'd recommend and remind people to wash their hands thoroughly after handling money to help prevent spreading these harmful bacteria.

Source: Hannah Maundrell, Editor in Chief of money.co.uk

Glossary of bacteria