Study Reveals High THC Levels in Deceased Drivers

A recent study has uncovered a concerning percentage of drivers who died in traffic accidents, with more than 40% of them found to have active tetrahydrocannabinol (THC) in their blood. This high percentage raises alarms about the impact of cannabis use on public safety, especially since the average THC levels in the blood were significantly higher than the impairment thresholds in most states.

Comprehensive Analysis of Six Years of Data

Researchers reviewed forensic records from Montgomery County, Ohio, covering the period from January 2019 to September 2024. The study included 246 deceased drivers who were tested for THC following fatal accidents. This study is particularly relevant as it spans the period when recreational cannabis was legalized in the state in 2023, giving researchers a chance to assess the impact of these legal changes on driver behavior.

Dr. Akpofure Ike, the study’s lead author and a professor of surgery at Wright State University, noted that the average THC level of 30.7 ng/mL indicates cannabis consumption shortly before driving, suggesting recent use rather than residual presence.

Main Findings of the Study

The study showed that 103 drivers (41.9%) tested positive for THC, with annual rates ranging between 25.7% and 48.9%. Legalization had little effect on the percentage of drivers testing positive before or after legalization (42.1% versus 45.2%), indicating that the legal status did not influence the behavior of those choosing to drive after use.

The study also highlighted that THC blood levels drawn by the coroner within hours of death provide an accurate picture of the driver’s mental state at the time of the accident. Most states with legal driving limits set thresholds between 2 to 5 ng/mL, far below the average recorded in this study.

Need for Enhanced Public Warnings

Dr. Ike emphasized that public messages in recent years have focused solely on recreational legalization, stressing the urgent need to highlight the potential risks and harms. People should treat marijuana smoking like alcohol: do not smoke and drive.

The study’s co-authors, Louis Ngwaba, Clara Mosen Phillips, and Anna Cardosi, added that these findings serve as a warning to reconsider public policies related to cannabis legalization and its impact on public safety.

Conclusion

This study serves as a strong warning about the risks associated with cannabis use while driving. Although legalization does not directly affect the percentage of users among drivers, the high THC levels detected underscore the need to enhance public awareness of the associated dangers. Legislators and relevant authorities should take these findings into account to develop more effective public safety policies.