Aerospace Medicine Technical Reports

FAA Office of Aerospace Medicine
Civil Aerospace Medical Institute

Report No: DOT/FAA/AM-18/02

Title and Subtitle: Assessing Trends in Cannabinoid Concentrations Found in Specimens from Aviation Fatalities between 2007 and 2016

Report Date: May 2018

Authors: Norris A, Cliburn K, Kemp P, Skaggs V

Abstract: Marijuana continues to be the most commonly abused drug in the United States and is known to cause decrements in psychomotor performance. Delta-9-tetrahydrocannabinol (THC), the major psychoactive component of the cannabis plant and its major metabolite, 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (THCCOOH) are routinely tested for in fatal aviation accident investigations by the forensic toxicology laboratory at the Civil Aerospace Medical Institute (CAMI).

This study was initiated to examine the blood cannabinoid concentrations of THC and THCCOOH detected in victims of aviation accidents from 2007-2016 and follows a similar report from CAMI that covered the previous 10-year period (1997-2006) in which it was noted that these cannabinoids were increasing in concentration. There were 2,909 cases received by the Forensic Sciences Section at CAMI during the current study period, 99 of which (3.4%) were positive for THC or THCCOOH in at least one specimen-type (fluid or tissue).

When compared with the previous 10-year study, 2007-2016 showed a 433% and 23.5% increase in overall median blood concentration of THC and THCCOOH, respectively. However, over the 10-year period of the current study, the blood concentrations reflected a downward trend. The mean and median THC/THCCOOH concentration ratio was 0.62 (± 0.53) and 0.45, respectively, with some individuals having ratios > 1.0. The THC/THCCOOH ratios trended upward over the 10-year study period. Fifty-five cannabinoid-positive, medically certificated pilots and 1,918 controls were examined for any relationship between the presence of the cannabinoids and other variables of interest. This examination indicated that cannabinoid-positive pilots tended to be younger in age and were likely to have another impairing drug in their body at the time of the aviation accident.

This study contributes much needed data to scant research on postmortem cannabinoid concentrations and will assist with the interpretation of cannabinoid positive cases.

Key Words: Forensic Science, Toxicology, Marijuana, Pilot Fatalities, Civil Aviation, Accident Investigation

No. of Pages: 19

Last updated: Thursday, May 31, 2018