Drug abuse has become so rampant that one out of every 10 people are found with traces of cocaine or heroin on their fingerprints despite never even trying any.
Researchers behind the fingerprint test for detection of class A substances conducted another study involving 50 nonusers and another 15 who've confessed to using either of the two illegal drugs over the past 24 hours.
Before testing, drug-free participants were instructed not to wash their hands and their results turned out to be quite shocking.
Results Of The Fingerprint Test For Cocaine
Even when they've been clean their entire lives, approximately 13 percent of the fingerprints contained hints of cocaine and 1 percent of a metabolite of heroin.
Fortunately, the team at the University of Surrey developed a "cut-off" system to identify the samples with traces obtained through actual drug use, from those with environmental contaminants.
To test its effectiveness, drug-free participants were asked to shake hands with drug user before their fingerprints were once again collected for testing.
Based on the second set of results, people taking illegal drugs can pass on traces of the substances they use to others through simple and seemingly harmless gestures such as touching another person's hands.
"Believe it or not, cocaine is a very common environmental contaminant - it is well known that it is present on many bank notes," points out University of Surrey's Forensic Analysis Lecturer Melanie Bailey in a news release.
Nonetheless, researchers claim that the cut-off level has proven to be accurate, and will contribute another "robust layer" to improve fingerprint drug testing.
Accurate And Non-Invasive Fingerprint Drug Testing
In 2017, Bailey led the same team in developing a non-invasive and effective way to find out if a person is positive for cocaine. All it requires is a clear fingerprint and chromatography paper.
When drug users are on cocaine, their bodies excrete benzoylecgonine and methylecgonine. Both of these chemicals are retained as fingerprint residue and are detectable even after thorough handwashing.
Paper spray mass spectrometry guarantees 99 percent accuracy and results can be reviewed in just a matter of two minutes. Soon, this timeframe will be reduced with the completion of a 30-second method. Researchers say it's still in the works.
"As with previous methods we have developed, it is non-invasive, hygienic, and can't be faked - by the nature of the test, the identity of the subject, and their drug use, are all captured within the sample itself," explains Bailey in a separate report.
The device used for fingerprint drug testing is currently as large as a conventional washing machine. Bailey's coauthor and colleague, Catia Costa, suggests a smaller portable version for law enforcement agencies in the future.
