A new study shows that traffic deaths rose temporarily in three states where recreational marijuana is approved and then dropped again, according to an article by The Verge.

Currently, 33 states have legalized medical marijuana and 10 have legalized recreational marijuana.

A study published in the journal Addiction found that, on average, Colorado, Oregon and Washington state (all of which have legalized medical marijuana) had about one additional traffic death per million residents, which adds up to about 170 additional deaths after the first six months of legalization, according to the article.

The study also reports that the increase in traffic deaths was only temporary, though, and the rates returned to normal after about a year.

Study co-author Tyler Lane, a post-doc in the School of Public Health and Preventive Medicine at Monash University in Australia, said that this could be caused by the legalized recreational marijuana initially leading to newer, more inexperienced users which, in turn, caused more accidents, according to the article.

To read the full article, click here.