Contact highs can lead to a failed drug test

By Oscar Pascual |

If you’re trying to pass a drug test, it’s probably a good idea not to hang out in a dorm room hotbox.

People who are exposed to marijuana smoke can actually receive a contact high and show detectable levels of the drug in urine or blood tests, a recent Johns Hopkins University study found.

But don’t worry — it only happens under the most extreme circumstances.

“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,” said Evan S. Herrmann, the study’s lead author and postdoctoral fellow in psychiatry and behavioral sciences at Johns Hopkins School of Medicine. “But this only happens under a very extreme situation.”

In the first study of its kind, Hermann’s team asked six marijuana smokers and six non-smokers to relax in a Plexiglass and aluminum chamber roughly the size of a dorm room. All six smokers were given 10 joints to smoke, each containing one gram of high-potency pot. They were instructed to smoke at their leisure for one hour while the six non-smokers sat next to them.

The room’s ventilation system was turned on during certain sessions, while researchers restricted the chamber’s airflow during others. Participants then completed a series of surveys and tasks to determine detectable levels of THC, as well as impairment.

“Our results are pretty consistent with what we expected,” Herrmann said. The new findings confirm “it’s really hard to get a positive [drug test result] from passive smoke unless you’re in an extreme scenario,” he said.

Under unventilated conditions, nonsmokers reported feeling high, and even had detectable levels of THC in their blood and urine up to 22 hours after being exposed. Nonsmokers in ventilated rooms did not feel impaired or high, nor did they test positive for THC levels in urine.

So if you’re trying to land a new job or even get drafted by the NFL, make sure to avoid hotboxes at all costs.

“We modeled the worst-case scenario,” Herrmann said. “You are in an enclosed room for an hour with 15 grams of cannabis being smoked.”

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