The university researchers concluded that legal tender in Sweden is near the top of the bacteria charts with an average of 39,600 bacteria per note. Only the Danish krone was dirtier, with 40,266 bacteria.
European banknotes carry an average of 26,000 bacteria.
This is more than just an academic calculation.
Ian Thompson, professor of engineering science at Oxford, says in a release that 26,000 bacteria is more than enough to pass on an infection.
Previous studies have shown that bank notes can be contaminated with harmful bacteria that can cause respiratory, urinary, and wound infections and other diseases.
The Oxford study looked at the currency used in 15 countries and found that the euro is the cleanest of them all, with just 11,066 bacteria.
Thompson has called for wider research into the spread of bacteria resistant to antibiotics through the global movement of money.
Sweden’s Riksbank, responsible for producing the nation’s money, is planning to introduce new and redesigned banknotes in early October 2015.
It is not clear whether the new notes will be equally bacteria-prone.
Source: The Local Switzerland, where the cash is also filthy, to be franc.