The prevalence of drugs and alcohol in fatally injured truck drivers.

To assess the impact of alcohol and other drug use in the trucking industry, the National Transportation Safety Board, in collaboration with The National Institute on Drug Abuse investigated fatal-to-the-driver trucking accidents in eight states over a one year period. Comprehensive drug screens were performed on blood specimens collected from 168 fatally injured drivers. One or more drugs were detected in 67% of the drivers and 33% of the drivers had detectable blood concentrations of psychoactive drugs or alcohol. The most prevalent drugs were cannabinoids and ethanol, each found in 13% of the drivers. Cocaine or benzoylecgonine was found in 8% of the cases. Seven percent of the driver's blood specimens contained amphetamine or methamphetamine and 7% contained phenylpropanolamine, ephedrine, or pseudoephedrine. A panel of toxicologists reviewed the accident investigation report and the toxicology findings for each case and determined that impairment due to marijuana use was a factor in all cases where the delta-9-tetrahydrocannabinol concentration exceeded 1.0 ng/mL and that alcohol impairment contributed to all accidents where the blood alcohol concentration was 0.04% wt/vol or greater. In 50 of 56 cases where psychoactive drugs or alcohol were found, impairment due to substance use contributed to the fatal accident.