A new study is to appear in Forensic Science International entitled Distribution of cocaine on banknotes in general circulation in England and Wales (C.G.G. Aitken, A. Wilson, R. Sleeman, B.E.M. Morgan, J. Huish). It concludes that there is no variation in the distribution of illicit drugs - cocaine in the case of the study - on banknotes in general circulation. The study was conducted in response to a 2014 court ruling (R. v. Rashid and others, [T20147216] (19th January 2015) and to review the findings of a similar study conducted in 2007. That study spawned the Mass Spec Analytical database of drug traces on banknotes, believed to be the largest of its kind in the world. It has been continuously updated weekly (at time of writing more than 118,000 banknotes tested) with new data since its creation in 2004.
Whilst the 2007 study is a very good investigation of the factors influencing the contamination of UK banknotes with drugs of abuse, it was seen to be useful in response to frequent questions in court to revisit the study in today’s context.
Following discussions with experts at the Bank of England, it was learnt that more than 75% of all banknotes issued are circulated via automatic telling machines (ATMs), the rest goes to banks, Post Offices and other outlets. Money is paid by businesses into banks, and this is typically returned to one of approximately 20 −25 cash redistribution centres within England. Certain larger retailers also send money directly to these centres. At the centres, money is sorted and unfit notes are weeded out and sent back to the Bank of England for processing and destruction.
For this study, access to unfit notes was requested from the Bank of England. It is not known whether or not banknotes continually build up contamination every time they pass through the banking system, or whether they reach an equilibrium state whereby the amount of drug abraded off is equal to the amount deposited, or whether some other explanation needs to be invoked for the quantity of drugs on the notes. However, it is reasonable to assume that older notes are likely to be the most worn, and therefore most likely to be declared Unfit, and it is also reasonable to assume that older notes are likely to have had the most exposure to ‘environmental contamination’ with cocaine.
It is always possible to argue that more is better. However, the data collected and analysed in the 2007 study and the results of this new study provide evidence that the current database of banknotes used by Mass Spec Analytical to represent banknotes in general circulation has been confirmed as fit for purpose. The new study also noted that, whilst it may be true, as noted in R. v. Rashid and others (p.31), that the quantities of cocaine on banknotes have increased in the time since the study reported on in 2007 was conducted, this current study provides no evidence to suggest the variation in quantities of cocaine has changed.
The study is available here.