Ninety-seven percent of all U.S. money contains traces of cocaine.

In the course of its average 20 months in circulation, U.S. currency gets whisked into ATMs, clutched, touched and traded perhaps thousands of times at coffee shops, convenience stores and newsstands.And every touch to every bill brings specks of dirt, food, germs or even drug residue.
Research presented previous findings that 97 percent of paper money circulating in U.S. cities contains traces of cocaine.