Cocaine Cash

Was watching a National Geographic podcast the other day and was blown away when they said that 90% of British paper money contained traces of cocaine. They also mentioned the dormant germs and bacteria on all notes.

Then I found a seperate story that stated 80% of American notes also bear traces of cocaine.

Talk about dirty money!

90% is a little high. I remember hearing a lower number than 80% for the US currency as well. Is this a trustworthy source?