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Motor vehicle drivers

THC Levels in Deceased Drivers Far Exceed Safety Threshold

Strategic Insights

— 1 min read

Researchers have found that over 40% of drivers involved in fatal motor vehicle collisions had active delta-9-tetrahydrocannabinol (THC) in their system, with average blood levels significantly exceeding those considered to cause impairment. The study analyzed coroner records from Montgomery County in Ohio and noted that the average THC level was 30.7 ng/mL, far surpassing the typical state-legal limit of 2-5 ng/mL. Despite the legalization of recreational cannabis in 2023, the study's findings suggest that the public health risks associated with driving under the influence of marijuana remain unchanged.

Key Takeaways:

  • The study found that 40.4% of deceased drivers tested positive for active THC in their system, with an average blood level of 30.7 ng/mL.
  • The researchers analyzed coroner records from Montgomery County in Ohio, covering a period from January 2019 to September 2024.
  • The study period included the state's legalization of recreational cannabis in 2023, highlighting that the risks associated with driving under the influence of marijuana remain unchanged.
  • Dr. Akpofure P. Ekeh, lead author of the study, emphasized that the average blood THC level in the study was far higher than the typical state-legal limit of 2-5 ng/mL.
  • The researchers noted that blood THC levels are typically drawn by the coroner within hours of death, providing an accurate snapshot of a driver's state at the time of the crash.
  • Co-authors Lois Nguapa, Clara Mussin Phillips, and Ann Cardosi, all contributed to the study with no relevant disclosures.
  • The study's findings highlight the importance of treating marijuana use like alcohol consumption, with Dr. Ekeh warning that people should "don't smoke and drive."

Statistics:

  • 40.4% of 246 deceased drivers tested positive for active THC in their system.
  • Average blood THC level: 30.7 ng/mL.
  • Typical state-legal limit for THC: 2-5 ng/mL.
  • Study period: January 2019 to September 2024.
  • State's legalization of recreational cannabis: 2023.

Sources:

  • Ekeh A, et al. Cannabis Prevalence in Drivers Involved in Motor Vehicle Crash Fatalities over a 6-Year Period, Scientific Forum, American College of Surgeons (ACS) Clinical Congress 2025.

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