Cocaine on every bank note

Every single bank note from a random sample analysed by Irish researchers has tested positive for cocaine.

The news is reported in the latest edition of the Royal Society of Chemistry journal The Analyst.

A team based at Dublin City University carried out the testing on 45 notes, ranging in value from five to 50 euros. All of them tested positive for various amounts of cocaine, with three also testing positive for heroine.

The researchers also tested three previously un-circulated notes as a control, all of which tested negative for illicit drugs.

The study is the largest of its kind ever carried out in Ireland.

PhD student, Jonathan Bones, who carried out the research working under the supervision of Dr Brett Paull at DCU's National Centre for Sensor Research (NCSR), said he was surprised by the findings.

He said: "The most recent survey carried out in the US showed 65 percent of dollar notes were contaminated with cocaine. However, the 100 percent rate uncovered in this project was surprising.

"Although not a quantitative measure, the presence of illicit substances on banknotes in general circulation provides an indication of the degree to which substances are being used by the community."

The cotton structure of euro notes absorbs chemical residues, including cocaine, and the team used a newly "optimised" chromatography and mass spectrometry technique to analyse the various notes.

The study found nearly two thirds (62 per cent) of the notes were contaminated with levels of cocaine at concentrations greater than two nanograms per note, with five percent of the notes showing levels greater than 100 times higher, indicating suspected direct use of the note in either drug dealing or drug inhalation.

The other notes contained only "ultra-trace" quantities of cocaine, which could have come from contact with other contaminated notes - which may have occurred from contaminated surfaces or within bank counting machines.

The highest amounts of cocaine residues were found on 20 and 50 euro bank notes, as compared to five and 10 euro notes.