WASHINGTON (AFP) – - US paper currency is roughed up and often soiled in circulation, but a study has found that some 90 percent of greenbacks contain traces of cocaine, giving new meaning to the term “dirty money.”

That is a nearly 20 percent jump over a similar study conducted two years earlier where 67 percent of dollar bills were shown to contain cocaine traces, according to researchers who presented the study Sunday at the annual National Meeting of the American Chemical Society.

The startling discovery points to the continuing widespread use of cocaine in the United States, one of the world’s biggest consumers of the drug.

The capital Washington topped US cities, with 95 percent of banknotes analyzed from there found to contain minute amounts of cocaine.

Money is known to get contaminated with cocaine when drug dealers make a transaction or when users snort the drug using a rolled bill.

But the study said the large-scale contamination takes place when the notes are whisked into currency-counting machines.

Evidence of the drug were more common in large cities like Baltimore, Boston and Detroit, while the cleanest bills were collected from Salt Lake City, Utah, the country’s Mormon hub.

Full Story: AFP/Yahoo SG