This paper presents some of the results from a study, conducted by TRL for the Department for Transport, to establish the incidence and types of drugs present in evidential blood samples taken from drink-drivers. These blood samples were obtained during the period 1997 to 1999 and were analysed by the Forensic Science Service (FSS) for the presence of drugs. This subset of 2000 was randomly chosen by the FSS from the complete set of evidential blood samples obtained for England and Wales during that period. The distribution of blood alcohol concentrations (BAC) in the subset of 2000 samples was similar to that in the complete set of samples, which suggests that the subset is representative of all the blood samples taken and indicates that it is representative of drug use among drink-drivers in this BAC range. The results show that almost 23% of drink-drivers tested positive for a single drug and in over three quarters of these drink-drivers this drug was cannabis. Four per cent of the drink-drivers tested positive for multiple drugs. The incidence of illicit drug use for drugs other than cannabis was small, the incidence of amphetamines was about 1 % and neither cocaine nor methyl amphetamines was detected in single drug use. The high incidence of cannabis relative to other illicit drugs may be explained by its common usage and the long period after consumption that it remains detectable in the body. Results are presented with regard to age and gender of the drink-drivers, single and multiple drug use and blood alcohol levels. (Author/publisher)
Abstract