SPOKANE, Wash. — Most teens in Washington state have begun using marijuana less since it was legalized in the state, according to a study led by a WSU College of Nursing Assistant Professor.

The study, led by WSU College of Nursing Assistant Professor Janessa Graves, showed that the only group of teens who reported even a slight uptick in usage was 12th graders who work 11 or more hours a week, according to a WSU press release. 

Usage among 8th and 10 graders "went down significantly," according to the release. Those seniors who don't work also saw a decrease, while levels stayed close to even for seniors who worked less than 11 hours a week.

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After legalizing marijuana in the state, 4.8 percent of non-working eighth graders reported using the substance in the last 30 days, while their working peers reported at a much higher 20.8 percent, according to the release.

For 10th graders, 33.2 percent of those who worked 11 or more hours reported using marijuana in the last month, compared to 13.9 percent for the group as a whole, according to the release.

High school seniors that worked reported at a rate of 36.7 percent as compared to 20.5 percent among non-working 12th graders.

The data used comes from the state's Healthy Youth Survey conducted in 2010 and 2016. Jobs not counted for those working while in high school included household chores, babysitting and yard work, according to the release.

"Kids who work more often use substances, that's not a shock," Graves said. 

She also said that "kids learn a lot by working, in terms of responsibility" and that data shows that kids who work tend to engage in adult behaviors earlier in life.

For parents worried about their children using marijuana underage, Graves urged them to be thoughtful of their child's workplace environment and also encouraged employers to take zero-tolerance stances in regards to adult employees providing controlled substances or encouraging their use to underage coworkers.

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