Illegal drugs are so common that 13 per cent of people have traces of cocaine on their fingers even though they don’t take drugs, a new study has revealed.
The most common drug found was cocaine, but one per cent had come into contact with heroin, according to University of Surrey researchers.
Dr Melanie Bailey, Lecturer in Forensic Analysis at the University, said: ‘Believe it or not, cocaine is a very common environmental contaminant.
‘It is well known that it is present on many bank notes. Even so, we were surprised that it was detected in so many of our fingerprint samples.’
Illegal drugs are so common that 13 per cent of people have traces of cocaine on their fingers
The team tested the fingerprints of 50 drug free volunteers and 15 drug users in the UK who testified to taking either cocaine or heroin in the previous 24 hours.
The results showed that the unwashed hands of the drug-free volunteers still found traces of class A drugs.
Around 13 per cent of fingerprints were found to contain cocaine and one per cent contained a metabolite of heroin.
To test the possibility of transferring drugs through a handshake, drug free volunteers were asked to shake hands with a drug user.
Fingerprints were then collected from the drug free volunteers after contact.
Although cocaine and heroin can be transferred by shaking hands with a drug user, the cut-off level established allowed researchers to distinguish between drug use and secondary transfer.
Even after washing their hands, they were able to tell who had come into contact with environmental contaminants and those who were genuine drug users.
Dr Bailey added: ‘By establishing a threshold for significance on a fingerprint test, we can give those tested the piece-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.’
Lead author of the paper published in Clinical Chemistry, Mahado Ismail, 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.
‘Our study will help to add another robust layer to fingerprint drug testing.’ The study was co-funded by Intelligent Fingerprinting, developers of the world’s first commercially-available portable drug test that works by analysing the sweat from a fingerprint sample.
Forensic analyst Dr Melanie Bailey said: ‘It is well known that it is present on many bank notes’
According to Intelligent Fingerprinting’s CEO, Dr Jerry Walker: ‘This important study confirms the University of Surrey’s position as one of the world’s foremost academic research groups when it comes to fingerprint diagnostics using mass spectrometry.
‘Critically, it also helps to establish a quantifiable high threshold for environmental drug traces, further establishing the validity of our commercial fingerprint-based drug test for cocaine, opiates, cannabis and amphetamines.’
Cocaine is deemed the world’s second favourite illegal drug, after cannabis, and has an older user base – dubbed ‘silver snorters’.
It is estimated almost 750,000 adults in England and Wales use cocaine each year.
One in ten Britons have tried cocaine at least once, despite it being deemed a Class A substance and in the same bracket at heroin.
In 2014, there were an estimated 1.5 million current users of the drug in the US – where the drug is in the second-most dangerous class, figures suggest.
It comes after worrying research last May suggested just a single snort of cocaine could be enough to get addicted.
The findings, made by scientists at McGill University, bolstered the growing evidence about cocaine’s damaging long term effects.
Ian Hamilton, a drug and mental health researcher from York University, told MailOnline that cocaine is ‘cheaper and purer than ever’ in the UK and is to blame for a spike in people seeking help on a cash-strapped NHS.