Traces of Drugs on UK banknotes

An inquiry conducted by law enforcement in the United Kingdom found that 11 percent of all banknotes circulating within the country had traces of cocaine on them. The 11 percent figure in 2011 was higher than the 4 percent figure reported in 2005.

Source: Alan Travis, “Cocaine found on 11% of UK banknotes,” Guardian, December 1, 2011.