Drug and Alcohol Concentrations of Drivers Involved in Fatal Motor Vehicle Accidents in British Columbia, Canada: A One Year Study

Wayne K. Jeffery*, MSc., Janna M. Leslie**, BSc. and G. William Mercer***, Ph.D.

*Section Head, Toxicology, Royal Canadian Mounted Police, Forensic Laboratory, 5201 Heather St., Vancouver, British ColumbiaV5Z 3L7, Canada

**Toxicology Section, Royal Canadian Mounted Police, Forensic Laboratory, 5201 Heather St., Vancouver, British Columbia, V5Z 3L7, Canada

***Senior Policy Analyst, B.C. Police Commission Ministry of Attorney General, 405 - 815 Hornby St., Vancouver, British Columbia, V6Z 2E6, Canada

The views expressed in this paper are those of the writers and do not necessarily represent those of any other individuals or of any organizations. Detail on the analyses presented in this paper can be obtained by writing either author.

ABSTRACT

Blood Samples of 41 female and 181 male fatally injured drivers were examined. Analyses suggested that drugs other than alcohol are contributing to fatal traffic accidents in British Columbia. Toxicological Analysis showed: alcohol alone (37%); alcohol-and-drugs (11%); and drugs alone (9%). The most frequently encountered drugs were alcohol (48%); tetrahydrocannabinol or its metabolite (THC/THCCOOH) (13%); benzodiazepines (5%); and cocaine (4%). Blood samples were screened by EMIT, capillary GC with NP and EC detection and LC with diode array detection. All samples were confirmed by GC/MS and quantified by GC with NP or EC Detection, LC with diode array (uv) detection or GC/MS.

INTRODUCTON

The present study was undertaken to address both the descriptive epidemiology and analytical epidemiology of drugs and alcohol in fatal accidents in British Columbia. Broad spectrum toxicological analyses on samples of fatally injured drivers' blood were carried out by the Royal Canadian Mounted Police (RCMP), Forensic Laboratory (toxicology section) in Vancouver B.C. The samples were obtained through the office of the Chief Coroner, Ministry of Attorney General, and were collected at autopsy for drivers who had died within 24 hours of the traffic accident, between October 1, 1990 and October 31, 1991.

TOXICOLOGICAL ANALYSES

The following analytical techniques outlined in Figure 1 were used: Toxi-lab Thin Layer Chromatography, Gas Liquid Chromatography (NP, EC and FID detection), High performance Liquid Chromatography, Enzyme Multiplied Immunoassay Technique (EMIT) and Gas Chromatography/Mass Spectrometry. In general, urine (where submitted) analyses were used for screening purposes, and blood samples were primarily used to confirm and quantify drugs intially identified in the urine. For urine samples the following tests were carried out: colour tests, modified EMIT (Asselin and Leslie, 1992), Toxi-lab and a GC/NP screen of the Toxi-lab extract. For blood samples the following tests were carried out: Alcohol screen, GC/EC screen for benzodiazepines, GC/NP screen for basic neutral compounds, HPLC screen for acidic neutral and modified Emit if no urine was submitted. All compounds were quantified by the methods outlined in Figure 1 and confirmed by GC/MS.

Figure 1
Analytical Techniques

RESULTS

It must be stressed that virtually all chemical analyses presented herein probably underestimate the extent and degree of alcohol and/or drug use. Blood samples were taken at autopsy from drivers who died within 24 hours of the accident. Drugs and alcohol would have been metabolized until the time of death, while any intravenous solutions administered during medical intervention would dilute alcohol (BAC) and drug blood concentrations. Consequently, unless death occurred instantly at the accident, levels revealed through toxicological analyses are lower than those at the time of the accident, and drugs like tetrahydrocannabinol may be present only as metabolites.

Chemical States

In order to aid in conceptualization of combinations of chemical states, the sample was grouped into 4 broad categories: no detected alcohol or drugs; detected alcohol and no detected drugs (+A/0D); both alcohol and drugs detected (+A/+D); and no alcohol, only drugs detected (0A/+D). The results are shown in Figure 2.

Figure 2
Chemical States

Alcohol and Drug Levels

The alcohol levels of the total group, + A/0D, and + A/+D are shown in Figure 2. The drugs found in the + A/+D, and the 0 A/+D group are shown in Tables 1 and 2 respectively.

Table 1
Chemical State + Alcohol in mg% + Drug in ng/mL.

Table 2
Chemical State 0 Alcohol + Drug in ng/mL.

Chemical Frequencies and Magnitudes

109 persons (48% of the sample) tested positive for alcohol, with a mean BAC was 164 mg%. 41 females in the sample, 27% (11), tested positive, with a mean BAC of 189 mg%. 186 males in the sample, 53% (98), tested positive, with a mean BAC of 161 mg%.

Tetrahydrocannabinol and its Metabolite (THC and THCCOOH)

29 persons (13% of the sample) tested positive for THCCOOH, with a mean level of 14.7 ng/mL. For the males, 14% (26) tested positive for THCCOOH, with a mean level of 14.7 ng/mL, while for the females 7% (3) tested positive with an average level of 15.3 ng/mL. All of the 12 persons (5% of the sample) who tested positive for THC also tested positive for THCCOOH, with an average level of 3.5 ng/mL. Of the females, 2 (4%) tested positive at a mean of 5.9 ng/mL, and of the males, 10 (5%) tested positive at 3.1 ng/mL.

In the + A/+D group 20 out of the 26 cases (77%) contained THC and/or metabolite. Eight out of the 20 cases contained both THC and metabolite. In the 12 cases which only contained THCCOOH, 5 cases contained other drugs: two cases contained cocaine at 15 and 17 ng/mL, two cases contained diazepam and nordiazepam, at therapeutic levels, and the last one only contained benzoylecgonine.

In the + alcohol group only 3 cases were less than 100 mg%. The average BAC was 156 mg% (range 20-251). In the 0 A/+D group 9 of the 21 cases contained THC and/or metabolite, of these 5 contained THC also. Of the five cases containing only THCCOOH, 3 contained other drugs. One contained cocaine at 13.1 ng/mL, diazepam at 1310 ng/mL, and nordiazepam at 1400 ng/mL (high therapeutic to toxic levels); another contained only a low therapeutic level of diazepam (92.5 ng/mL), and third case only contained benzoylecgonine.

The hours from smoking were calculated according to Huestis et al (1992). In the 12 cases where this was done, the average time from smoking was 2.3 hr. In the +A/+D group the time was 2.6 hours, while in the 0A/+D group the time was 1.7 hours. If the THC levels are considered, the average THC level in the +A/+D group was 2.9 ng/mL: in the 0A/+D group, the level was 4.7 ng/mL. Although there was not enough data to determine statistical significance, it may indicate a trend in the negative alcohol group to a higher THC level and smoking closer to the time of accident.

Cocaine

Ten subjects (4% of the sample) tested positive for cocaine and/or metabolite. Six tested positive for both cocaine and metabolite, 3 in both the +A/+D and 0A/+D with an average cocaine level of 131 ng/mL. All were males, and represented 5% of the males. Of the 4 cases which tested positive for only cocaine metabolite, 2 cases also tested positive for THCCOOH. One case which had a low level of cocaine contained diazepam and nordiazepam at 1310, 1400 ng/mL respectively (high therapeutic to toxic levels).

Benzodiazepines: Eleven subjects tested positive for diazepam and/or metabolite and one subject for temazepam (5% of the sample). The mean diazepam level was 405 ng/mL and the nordiazepam level was 1480 ng/mL. All levels were in the therapeutic to toxic range. All were males, and comprised 6% of the males in the sample.

Other Drugs

Six cases contained other drugs: (1) ephedrine at 20 ng/mL; (2) carbon monoxide at 14%, (3) Doxylamine, an antihistamine (insufficient sample to quantify), (4) Imipramine at 140 ng/mL (high therapeutic level), (5) butalbital at 1100 ng/mL (high therapeutic level), (6) codeine at 30 ng/mL plus temazepam at 130 ng/mL.

CONCLUSION

The total involvement of alcohol in Fatal Motor Vehicle Accidents was 48% and alcohol plus drugs was 20%.

REFERENCES

Asselin, W.M., and Leslie, J.M. J.Anal Tox. 16: 381-388, 1992.

Huestis, M.A., Henningfield, J.E., and Cone, E.J. J.Anal.Tox. 16: 283-290, 1992.