Can You Really Get A ‘Contact High’ From Marijuana?
The study volunteers had never smoked marijuana before, but they all piled into a small car for 30 minutes, joints in-hand. Some smoked while the rest were instructed to breathe normally.
The researchers wanted to investigate the same question recently raised by the onscreen antics of Anderson Cooper 360 reporter Randi Kaye, who spent a week reporting on the legalization of marijuana in Colorado: Can you really get a “contact high” from people getting high around you?
According to the Internet, yes and no. An entire thread on Marijuana.com tells stories of the elusive contact high. One comment claims a girl lied to her probation officer that her friend blew smoke in her face, while another tells about getting stoned from her mom.
Similarly, the researchers’ findings, published in the Journal of Forensic Science in 1985, were inconclusive — just as most of the other research has been. The Norwegian study only included ten volunteers, and the smokers were told to inhale as little as possible, leaving plenty to breathe for the non-smoking volunteers.
Under those artificial conditions, the researchers found that only certain participants had levels of active agents like THC high enough to generate mental and physiological changes. But none of the participants actually felt high — a finding that appeared in a similar study in which experienced users were told smoke normally.
In fact, the hot-box experiment sounds like a drag for all involved. ” No subject experienced any feeling of euphoria,” the researchers noted. And “the discomfort caused by the heavy Cannabis smoke during the exposure period was universal.”
Still, a contact high might be possible, a later study in Clinical Pharmacology and Therapeutics found — but only under extreme conditions. The researchers instructed their subjects to sit quietly wearing colored goggles while a machine in the middle of the room “smoked” 16 marijuana cigarettes in one hour.
While the physiological effects of the passive smoke inhalation varied, the subjects did report a high this time. No reaction to placebo cigarettes further corroborated the results.
But the researchers estimated that inhaling passive smoke from 16 joints in one hour had a similar effect to actually smoking just one, and they emphasized that different people can react very differently while inhaling similar amounts.
For clarification on the real-life application, we turned to Cecilia J. Hillard, a professor of pharmacology and the director of the Neuroscience Research Center at the Medical College of Wisconsin, who has studied marijuana extensively.
In her expert opinion, she told Business Insider in an email, “the ‘contact high’ is purely a psychological phenomenon.” The lungs, she explained, are extremely good at trapping the THC in marijuana, ” and little residual THC is present in the exhaled air.”
In other words, people ” may experience runny noses or itchy eyes from the smoke” when others smoke marijuana, but they aren’t likely to be hit with enough THC to feel high.
A more recent study, published in 2010 in the Journal of Analytic Toxicology, supported this idea, concluding that passive exposure to marijuana smoke under real-life conditions would only leave “trace amounts” of THC in the blood.
So was Randi Kaye actually high when she couldn’t stop giggling during her interview with Anderson Cooper?
After all, she spent an entire day riding around in a car full of smokers, reaching levels of exposure greater than most of the experiments on the effects of passive smoke.
Kaye’s high is possible — but not probable. Her demeanor was likely influenced as much by the people she spent time with and a placebo effect as by actual THC.
Most people who think they are experiencing a “contact high” should keep in mind that, as an old study in the Journal of Abnormal Psychology concluded, “social setting and belief interact with smaller doses of marijuana.”
In other words: Being around a little bit of smoke probably won’t get you high, but when you factor in the placebo effect of that same smoke, you might just end up with a case of the giggles.
Researchers had their subjects sit quietly wearing colored goggles while a machine in the middle of the room "smoked" 16 marijuana cigarettes in one hour.
What are the side effects of secondhand marijuana smoke?
Marijuana, the dried leaves and flowers of the cannabis plant, is known for its psychoactive properties. When a person smokes or ingests it, they experience a high. But what about secondhand smoke?
When a person does not smoke marijuana themselves but instead inhales the smoke that someone else breathes out, this is called secondhand marijuana smoking. Some people may be concerned about the risks of breathing this secondhand smoke.
Keep reading to learn more about the effects that secondhand marijuana smoke can have on a person and the possible risks.
Share on Pinterest A person is unlikely to get high from breathing in secondhand marijuana smoke.
Studies have shown that although possible, it is unlikely that a person who breathes in secondhand marijuana smoke will get high. A high that an otherwise sober person experiences when they are near someone under the influence of recreational drugs is known as a contact high.
The chance of a person becoming high after inhaling secondhand marijuana smoke can increase if they are very close to someone who is smoking. The risk also increases if the person smoking is using marijuana with a higher tetrahydrocannabinol (THC) level.
THC is one of several chemical compounds in the cannabis plant, which are called cannabinoids. It is THC that causes the mind-altering, or psychoactive, effects of weed. Naturally, a higher level of THC means a more potent effect.
If there is poor or no ventilation, the likelihood of a person becoming high from the surrounding smoke drastically increases, too.
In short, for a contact high to be possible, a person would need to be in close contact with highly concentrated marijuana smoke for an extended period in a poorly ventilated area.
People who inhale secondhand marijuana smoke may feel the following side effects:
- burning, itchy, or red eyes
- dry mouth
- increased appetite
- rapid heartbeat
- a sensation of time slowing
It is also possible that a person who has had exposure to high levels of marijuana smoke in a nonventilated area may experience slight impairments in their memory and motor skills. This effect can be dangerous if a person is driving or operating machinery.
Exposure to secondhand marijuana smoke carries some other risks, including:
Some workplaces require employees to undergo regular drug tests to make sure that they are drug-free and fit to work. Depending on the sensitivity of the drug test, a positive result may be possible in people who have not directly consumed marijuana but have inhaled secondhand smoke.
In one study, researchers tested urine samples from nonsmokers after they spent an hour in proximity to people smoking marijuana. The researchers found that people who were near to marijuana smokers in poorly ventilated areas did test positive for THC in their urine, based on “commonly utilized cutoff concentrations.”
However, the lack of ventilation and strength of the marijuana had a significant effect on the results. Also, the drug tests took place over the period straight after the participants had inhaled the smoke.
Although the effects of secondhand cigarette smoke are well-known, experts know little about the associated health risks of secondhand marijuana smoke.
A 2016 study looked into the effects of secondhand marijuana smoke in rats. The researchers found that after a minute of exposure, the femoral artery’s response to increased blood flow became impaired for 90 minutes. In comparison, with cigarette smoke, this effect lasted only 30 minutes.
It is possible to conclude from these findings that secondhand marijuana smoke could have negative effects on the heart. However, researchers must continue to study this before making any firm conclusions.
A study into the effect of secondhand marijuana smoke on 83 children with parents who smoke found that almost half of the children had biological evidence of exposure to marijuana.
Although there was no evidence to link secondhand marijuana smoke to health issues in these children, the results are concerning, given the presence of potentially harmful chemicals in marijuana smoke.
Marijuana cigarettes contain various toxins and tars that are also present in tobacco cigarettes, leading researchers to believe that secondhand marijuana smoke possibly carries some of the same health risks as secondhand cigarette smoke. More research is necessary to confirm this, though.
Some people may worry about the side effects of secondhand marijuana smoke. Learn more about the potential risks of inhaling secondhand marijuana smoke here.