A new study on marijuana use is causing a great deal of concern among both proponents and opponents of legalization as it indicates that teens are starting to use it at an alarming rate as its reputation as a safe drug grows. The study, which is from the UC Davis Violence Prevention Research Program, found that teens in the state of Washington where marijuana was legalized saw an increase in pot use after the 2012 vote, as well as a large drop in the “perception of harmfulness,” according to a statement from JAMA Network Journals.

Teens in states where it is illegal to have marijuana had a drop in perception of harm by about 5 to 7 percent, compared to 14 and 16 percent for teenagers in Washington state where the drug is legal. Use of the drug also increased by 2 percent for 8th graders and 4 percent for 10th graders, compared to a 1 percent drop in states where it is not legal.

That’s concerning because more teens toking up won’t improve the public’s perception of the drug, and could result in resistance to making it nationally legal, or even slow down legalization efforts in other states.

The statement reads: “Marijuana use increased and the drug’s perceived harmfulness decreased among eighth- and 10th-graders in Washington after marijuana was legalized for recreational use by adults but there was no change among 12th-graders or among students in the three grades in Colorado after legalization for adults there, according to a new study published online by JAMA Pediatrics.”