You Can Fail a Drug Test Thanks to Contact High

It may take a whole lot of weed and a total lack of ventilation, but scientists say it's true: You can get contact highs from marijuana, with high-enough levels in your bloodstream to fail drug tests. So report Johns Hopkins researchers in the journal Drug and Alcohol Dependence. They rounded up healthy individuals ages 18 to 45 and tested their blood, urine, saliva, and hair. Then the scientists put 12 of the participants in a Plexiglas-and-aluminum smoke chamber the size of a dorm room and asked the six smokers among them to light up as many of the 10 single-gram high-potency joints as they pleased over the course of an hour in the presence of the six nonsmokers. (Participants were allowed to wear jumpsuits and disposable booties to protect their clothes, as well as goggles to prevent eye irritation, which must have been quite the look.)

It turns out that when the researchers ran the experiment without ventilation, participants had minor but detectably higher heart rates and performance impairments, and four of the nonsmokers failed multiple drug tests a day after exposure. When the room was ventilated, however, cannabinoids were so low as to even be undetectable in blood and urine tests. In fact, the only noticeable effect when ventilated is that even nonsmokers got the munchies, although researchers acknowledge that "lunch hour was approaching," reports New York. And while the researchers say their study highlights the potentially dangerous effects of secondhand smoke, they acknowledge that "it's really hard to get a positive [drug test result] from passive smoke unless you're in an extreme scenario," reports LiveScience. (Smoked pot as a young teen? You're probably shorter because of it.)