Narcotics are now so prevalent in society that many of us – regardless of drug use – have traces of cocaine and heroin on our fingerprints.
It turns out that even the most pious of people can no longer claim that they have never had contact with illegal narcotics, as a new study into drug prevalence on human skin has returned some rather interesting results.
According to the study conducted by a team from the University of Surrey and published to Clinical Chemistry, 13pc of those taking part in a test were found to have traces of class A drugs on their fingerprints, despite never using them.
To come to this conclusion, the team tested the fingerprints of 50 drug-free volunteers, and a further 15 who said that they had taken either cocaine or heroin in the previous 24 hours.
Despite their claims of being drug-free, the fingerprint scans showed that the unwashed hands of these volunteers had traces of class A drugs, with 13pc showing signs of cocaine and 1pc showing a metabolite of heroin.
By setting a ‘cut-off’ level, researchers were able to distinguish between fingerprints that had environmental contaminants from those produced after genuine drug use, even after people washed their hands.
To test the possibility that trace amounts could have been transferred via a handshake, drug-free candidates shook the hands of drug users, with their fingerprints scanned once again.
New means of drug testing
While both cocaine and heroin can be transferred through this interaction, the cut-off level established allowed researchers to distinguish between drug use and secondary transfer.
The researchers admitted that the results were rather surprising, even though it is common knowledge that cocaine is prevalent on many bank notes.
“By establishing a threshold for significance on a fingerprint test, we can give those tested the peace of mind of knowing that whatever the result of the test may be, it was not affected by their everyday activities or shaking hands with someone that had taken drugs,” said Dr Melanie Bailey, who was involved in the research.
The findings will help to see whether fingerprint scanning could be used for drug testing in the near future.
Mahado Ismail, lead author of the paper, said: “It’s clear that fingerprint testing is the future of drug testing. There are many factors that set fingerprint testing apart: it’s non-invasive, easy to collect and you have the ability to identify the donor by using the sample.”