We’ve all heard stories about getting a contact high — meaning when you’re in the same room as your buddies who are smoking and you get lit without even hitting the joint. You may have even heard stories of someone failing a drug test because they went to a party where people were smoking, even though they never took a single puff.
But is a cannabis contact high real or just a tall tale? Read on to get to the bottom of this cannabis mystery.
What the Research Says
We know there’s a ton of anecdotal evidence that supports the theory of a secondhand high, but is there any science to prove or disprove this concept? One 2015 study, in particular, seems to suggest that a contact high may be rooted in truth.
In this study, researchers gathered 12 participants, six of whom were smokers, and six of whom were nonsmokers. In their first experiment, they had the participants enter a small, unventilated room and gave each smoker 10 joints (our kind of research), each with a THC content of 11.3%. They also asked each subject to wear protective clothing so as not to mix up any of the final data with lingering smells.
Then, the smokers enjoyed each joint while sitting around a table with the nonsmokers over the course of an hour. Once the time was up, all of the participants left the room, discarded their protective clothing, washed their hands and faces, and proceeded to a different room to complete the study assessment.
This exact scenario was replicated in a second experiment, with one important exception: the small room was now ventilated. Believe it or not, researchers discovered significant differences between the two experiments — so let’s discuss.
In the first, where participants were essentially hotboxing the room with zero ventilation, the nonsmokers were indeed found to have detectable levels of THC in both their blood and urine tests. Researchers also added, “Exposure to secondhand cannabis smoke in an unventilated chamber the size of a small room produced minor increases in heart rate, mild to moderate subjective drug effects, and minor, but detectable, levels of performance impairment on some behavioral/cognitive assessments.”
So it’s true! When under extreme conditions, like in a tiny room without ventilation and tons of smoke going around in a short period of time, it is possible to feel high even if you haven’t smoked anything — you could even fail a drug test under the right circumstances.
However, in the second experiment, the ventilation made all the difference. Even though it was the same exact small room with the same exact amount of THC floating around, the non-smoking subjects did not have any detectable levels of THC or any other cannabinoids in their blood following the experiment. They also did not screen positive for THC in urine tests and did not report any psychoactive effects. In other words, this study proved that secondhand high is real, but it may only manifest itself in a noticeable manner under very specific circumstances.
And, unfortunately, we don’t have much data beyond this study to say whether or not these findings are true. While there is other research available, much of it is dated and does not take into account the potency of cannabis these days. With that said, these findings are incredibly persuasive but we need more research to certainly determine the specifics on secondhand high.
When all is said and done, it’s just courteous to be considerate with your smoke. If you’re in a comfortable environment, feel free to enjoy yourself as much as you want. Otherwise, you may want to ask others if they’re okay with smoke in the same room before sparking up your next joint — and if they are, you know where to stock up on the best buds.