Since the legalization of marijuana in Colorado, there has been an increase in hospital visits and calls to regional poison centers due to unintentional marijuana exposure among young children. Researchers from the University of Colorado evaluated the number of children with exposures before and after recreational marijuana was legalized.
Between 2009 and 2015 they found a rise in the annual number of unintentional pediatric exposures. On average, these children were about two years old. Most children ingested the drug in edible forms such as candies and baked goods. Almost half of the patients seen in the children’s hospital in the 2 years after legalization had exposures from recreational marijuana, suggesting that legalization did affect the incidence of exposures.
You can see the special report here: http://www.thenewsmarket.com/global/journal-of-the-american-medical-association/video/marijuana-exposure-increases-among-colorado-kids-since-legalization/a/46b2567f-c613-4115-b905-729b362d4246