Rising rate of marijuana exposure among children 5 years old and younger

The study, published online today in Clinical Pediatrics, found that the rate of marijuana exposure among children 5 years of age and younger rose 147.5 percent from 2006 through 2013 across the United States. The rate increased almost 610 percent during the same period in states that legalized marijuana for medical use before 2000.

In states that legalized marijuana from 2000 through 2013, the rate increased almost 16 percent per year after legalization, with a particular jump in the year that marijuana was legalized. Even states that had not legalized marijuana by 2013 saw a rise of 63 percent in the rate of marijuana exposures among young children from 2000 through 2013.

More than 75 percent of the children who were exposed were younger than 3 years of age, and most children were exposed when they swallowed marijuana.

"The high percentage of ingestions may be related to the popularity of marijuana brownies, cookies and other foods," said Henry Spiller, D.ABAT, a co-author of the study, toxicologist, and director of the Central Ohio Poison Center at Nationwide Children's. "Very young children explore their environments by putting items in their mouths, and foods such as brownies and cookies are attractive."

The study findings showed that most exposures resulted in only minor clinical effects, but some children experienced coma, decreased breathing, or seizures. The main psychoactive ingredient of marijuana, THC, can be especially high in marijuana food products, and that may have contributed to some of the observed severe effects. More than 18 percent of children who were exposed were hospitalized. These hospital admissions were likely due not only to the clinical effects, but also the need to investigate the circumstances that lead to the exposure in the home.

Overall, there were 1,969 young children reported to Poison Control Centers in the United States because of marijuana exposure from 2000 through 2013. While that is a relatively small number of total cases, the steep rate of increase in states that have legalized marijuana is reason for concern, said Gary Smith, MD, DrPH, senior author of the study and director of the Center for Injury Research and Policy at Nationwide Children's.

"Any state considering marijuana legalization needs to include child protections in its laws from the very beginning," Dr. Smith said. "Child safety must be part of the discussion when a state is considering legalization of marijuana."

Researchers recommend the same measures for commercially-available marijuana products that are now used to protect children from medicines and dangerous household chemicals, including requirements for child-resistant packaging and packaging that is not see-through. These same precautions need to be used for homemade marijuana products. If any marijuana products are in a household, they need to be kept up, away and out of sight of children, preferably in a locked cabinet.

Data for this study came from the National Poison Database System, the most comprehensive and accurate database available for investigation of poisonings in the United States. The study was conducted by researchers at the Center for Injury Research and Policy and the Central Ohio Poison Center, both at Nationwide Children's.