By Currency Research

The oft-circulated claim that a “microbial jungle” resides in the world’s wallets due to “dirty money” makes for a sensational, albeit misleading, headline. Currency Research believes such claims (i.e., cash is dirtier than any other commonly used item or causes health problems by transmitting diseases) are both irresponsible and unbalanced reporting:


Almost 60% of Europeans believe cash is the dirtiest item they come into contact with, ahead of escalator handrails, buttons on payment terminals and library books, according to a survey of 1,000 people released on March 25 by Mastercard.

Independent tests on European money conducted by a team of scientists at Oxford University in December 2012, revealed that the average banknote contains 26,000 bacteria, enough germs to make you feel nauseous, and possibly even spread disease.

To prevent infection, scientists suggest basic hygiene: Keep your hands away from your eyes, nose and mouth, and wash your hands often. 64

A recent Currency News article responded to these reports, referring to two studies out of the University of London that compare the bacterial levels of cash and payment cards:


One of the leading cashless players, Mastercard, is now using another argument to make its case – namely the cleanliness, or lack of it, of banknotes versus cards.

According to a new ‘independent’ report commissioned by Mastercard, which surveyed 1,000 people in 15 countries, Europeans believe cash to be dirty and riddled with bacteria, with more than half of those taking part thinking that notes and coins are the least hygienic items they come into contact with on a daily basis.

Mastercard claims that people are right to be concerned. According to the company, ‘for a significant amount of people it’s interesting to see a majority of Europeans prefer paying by card and find it a simpler, more straightforward way of paying. It’s now true to say that the majority also find it more hygienic’.

Putting such comments about Europeans preferring to pay by card aside, they clearly didn’t see the results of a research project undertaken by the London School of Hygiene and Tropical Medicine last year, which found that one in ten credit and debit cards contained faecal bacteria, with 8% of cards showing ‘gross contamination’ – meaning that they contained as much bacteria as an un-scrubbed toilet. By comparison, only 6% of cash showed gross contamination. The study had 272 participants, who offered up their hands, cards and money for testing.

In another study last year, this time by the University of London’s School of Biological and Chemical Sciences, an analysis of 200 banknotes and 45 credit cards showed that 26% of the former, and 47% of the latter carried high levels of bacteria. The survey compared these with the bacteria found on the average toilet seat. The seats examined had 10- 20 bacteria colonies forming in every 4 sq cm, while heavily contaminated notes had a similar or slightly higher number. However, heavily contaminated credit cards had more than 60 bacterial colonies forming in the same sized area.

Moreover, the Mastercard report concentrates on bacteria only. Everyday items are also subject to viral contamination – and viruses tend to last longer than bacteria on hard surfaces – eg. keys of a card acceptor at a POS terminal or, of course, plastic cards. 65

In a similar study, cash and credit cards are again found to carry comparative levels of bacteria:

A study [is] being conducted by SPC professor Shannon McQuaig that is looking at what type of money is spreading the most harmful types of bacteria.

McQuaig and a group of student volunteers, participating in the project called “Cash or Credit: spreading the wealth of virulence genes,” said they discovered the bacteria MRSA on both cash and credit cards, according to the report. 66

But how do these studies relate to the real world? Of course, regular hand washing and hygienic practices after the use of items in the public domain, including cash, cards, door handles, and hand rails, should continue to be recommended to the general public. Despite alarmist headlines suggesting otherwise, it is important to note that researchers have found cash to pose no danger to overall public health.

In 2010, a team of researchers at Ballarat University examined the bacterial content of circulating banknotes from 10 different countries, concluding that there should be no cause for alarm when handling cash:

Conclusions: A total of 1280 banknotes were obtained from food outlets in 10 different countries (Australia, Burkina Faso, China, Ireland, the Netherlands, New Zealand, Nigeria, Mexico, the United Kingdom, and the United States), and their bacterial content was enumerated.

It was found that pathogens could only be isolated after enrichment and their mere presence does not appear to be alarming. 67

Currency News reported on these findings in September 2010:


An international study into the levels of bacteria on banknotes has concluded that the levels of these are not dangerous.

The study, carried out at Ballarat University and led by Dr Frank Vriesekoop, analysed 1,280 notes collected from food retailers and cafeterias in at least ten countries – including Australia, Burkina Faso, China, Ireland, Mexico, the Netherlands, New Zealand, Nigeria, the UK and the US.

The study found that there was a correlation between the amount of bacteria and the substrate – with notes produced on polymer carrying less bacteria than paper notes. Unsurprisingly, it also found that notes from the richer and more developed countries had fewer bacteria than those of the poorer countries, where notes are typically in circulation longer.

Even so, according to Dr Vriesekoop, ‘we found very low levels of pathogenic bacteria in any of the banknotes, and never in alarming numbers.’

The researchers have, however, recommended that in food outlets the handling and food and the collection and exchange of money be physically separated, and preferably undertaken by different people. 68

To add to the debate, recent attention-grabbing headlines have proliferated to warn the unsuspecting public of the health dangers posed by another everyday item found to harbor significantly more bacteria than cash: mobile phones.


Your smart phone — it’s your social life, your workplace and your entertainment all in one. A new study says it’s also a festering cesspit of bacteria.

That’s right, the phone that goes with you into subways, public bathrooms and gyms — and then spends most of its time cozying up to your ears, nose and mouth — is far from clean, according to an investigation by the Wall Street Journal.

Tests of eight random mobile phones from a Chicago office found “abnormally high numbers of coliforms, a bacteria indicating fecal contamination,” reports the Journal, with about 2,700 to 4,200 units of the bacteria on each phone. 69

Currency Research concludes in agreement with the general consensus prevailing among the media and researchers cited above; good health is enhanced by frequent hand washing regardless of what is handled, whether it is a payment instrument or any other item encountered in day-to-day life.

This article has been posted with permission from Currency Research and is excerpted from The Case for Cash Part 1: Myths Dispelled. To request a copy of the full report or to learn more about Currency Research, please click here


Myth: Cash is “Dirty”