One in 10 people have traces of cocaine or heroin on their fingerprints. Scientists have found that drugs are now so prevalent that 13 percent of those taking part in a test were found to have traces of class A drugs on their fingerprints -- despite never using them. Source 6g.
Another reason to make sure that you're washing your hands often. Imagine getting cocaine in your system and then later be accused of using drugs in a hair follicle test.
International Level: New Activist / Political Participation: 16 1.6%