Think about how many hands the money in your purse or wallet has been through - even the crispest of notes.
It's enough to make even the least germ-phobic person shudder.
So it's perhaps no surprise to learn that our money AND credit and debit cards are the perfect breeding ground for nasties .
According to the latest figures from The Bank of England and The Royal Mint, there are currently 3 billion bank notes and 29 billion coins in circulation in the UK.
With this number of coins and notes passing between the UK population, there is a significant danger of passing on bacteria if certain hygiene habits are not properly followed.
But you probably already had an inkling that the contents of our purses and wallets can get a little grim.
What may surprise you to learn is that one bank note in particular is the dirtiest of them all.
As part of an experiment, a cross-section of payment methods were swabbed and sealed in petri dishes to ensure there was no cross-contamination.
The team then left the dishes in an open box in a warm place for five days and left the bacteria to thrive.
So, just how dirty is our cash?
The payment method that showed the greatest risk of hidden germs was the £10 note, as it showed substantial amount of bacteria growth over the five-day growth period. With 1 billion of these notes currently in circulation, this highlights the need for proper care when handling these notes.
In terms of coins, the 5p coin showed the greatest bacteria growth, however the cleanliest payment method of all was the credit card.
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Whilst it may not be a surprise to find that items passed from person to person can hide dangerous amounts of hidden bacteria, it seems the majority of the UK public are putting themselves in danger by putting their payment methods in their mouth.
Pharmaceutical Manager of Bupa Justin Hayde-West advises:
"Generally, we should wash our hands after using the bathroom, having contact with animals or pets, or after preparing raw foods such as chicken.
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"Washing our hands properly is important in terms of removing dirt, viruses and bacteria in order to avoid spreading illnesses. The World Health Organisation advises using hot running water and soap to clean the palms, fingertips and the often-forgotten gaps between the fingers where bacteria may hide.
"Cleaning your hands after more general tasks such as handling money is not strongly advised unless it feels particularly dirty since cleaning your hands far too frequently can have a negative effect on your skin."
