WASHINGTON (CBSDC)– A new study finds that exposure to secondhand marijuana smoke under severely unventilated conditions can lead to detectable levels of the drug in urine or blood.
LiveScience reports that individuals exposed by the smoke may even get a contact “high” or be unable to think clearly.
“If you’re going to breathe in enough passive cannabis smoke to feel high and potentially be slightly impaired, you could fail a drug test,” Evan S. Herrmann, the study’s lead author and postdoctoral fellow in psychiatry and behavioral sciences at Johns Hopkins School of Medicine, told LiveScience. “But this only happens under a very extreme situation.”
Marijuana is the world’s most commonly used illegal drug. The study found that many smokers are in enclosed spaces with poor ventilation while using the drug.
This is not the first study to indicate the correlation between social exposure and positive drug tests. However, studies from the 1980s were much more limited in that the marijuana used had lower potency. In addition, past studies did not account for ventilation levels or behavioral analysis. The latest study asks the important question: can you get high from secondhand smoke and can it trigger drug test failure?
Herrmann’s team recruited 20 healthy smokers and nonsmokers between the ages of 18 and 45. The participants were tested for blood, saliva, urine, and hair samples for cannabis biomarkers. Six smokers and nonsmokers were then asked to undergo two separate hour-long sessions in a plexiglass and aluminum smoke chamber which was about the size of a dorm room.
Each of the six smokers were given 10 one-gram high-potency weed cigarettes to smoke at their own pace. The nonsmokers were instructed to sit by their side during this time for the hour session.
One session had the room’s ventilation switched on while the other session restricted airflow in the chamber. After each hour-long session, participants in the study were asked biological, cognitive, and subjective survey questions for up to 34 hours after exposure.
The results suggest that it’s difficult to test positive for the drug after secondhand smoke exposure unless the conditions are extreme.
Nonsmokers in the “hot box” scenario did show slight impairments, reported feeling high, and tested positive for THC in their blood and urine up to 22 hours after exposure. Nonsmokers in the ventilated condition had lower levels of THC and did not report symptoms or test positive for the drug.
Researchers noted the the unventilated room does not represent most real-life situations and that they modeled it as a “worst-case scenario.”
A future study with an additional placebo group would help researchers determine whether the contact high feeling was due to the drug or from participants knowing they were being exposed to smoke.
“This study is really important because it adds to our limited knowledge of the direct effects of cannabis smoking and the potential dangers of second-hand smoke,” Ziva Cooper, an assistant professor of clinical neurobiology at Columbia University, told LiveScience.