Analysing Sobriety
The department of Forensic Medicine and Science (FMS) featured on the BBC’s Reporting Scotland programme recently as the blood alcohol limit for driving in Scotland was reduced from 80 to 50 milligrammes of alcohol per 100 millilitres of blood on the 5th December 2014.
As well as conducting the post-mortem toxicology casework for most of Scotland, the department - based in the Joseph Black Building - regularly conducts analyses on blood samples submitted by members of the public to determine whether their blood alcohol concentrations are above or below the legal limit allowed to be in charge of a motor vehicle. This analysis falls under the scope of the UKAS ISO/IEC 17025 accreditation status which the department has held since 2008 for several of the services it provides.
The change brings the drink driving law into line with other countries, such as Ireland, who introduced the reduced limit in October 2011, and France and Australia. However, FMS receives a large proportion of its blood alcohol workload from customers in England and Wales, where the limit remains 80 milligrammes of alcohol per 100 millilitres of blood. This meant that various aspects of the analysis and reporting has had to be amended to provide an appropriate service for customers from both areas.
It is expected that the department’s workload will increase further in March 2015, when legislation proscribing quantities of drugs in drivers’ blood is introduced in England and Wales. Currently it is illegal to drive whilst impaired through drugs in the whole of the UK, with impairment being exhibited by the failure of a Field Impairment Test (FIT), but the Drug Driving (Specified Limits) (England and Wales) Regulations 2014 will state levels of both prescribed and recreational drugs which must not be exceeded. FMS anticipates receiving a number of ‘B Samples’ taken by the police after stopping an individual at the roadside, which are only analysed by an independent laboratory if the accused disputes the original results.
No corresponding legislation is in place or imminent north of the border, but a study involving staff at FMS found that saliva is an appropriate matrix for roadside drugs testing. Another conducted by staff at FMS and published in the journal Forensic Science International in 2005 found that 16.8% of 1396 randomly-stopped drivers had at least one drug present in their saliva.