Since the change of medical marijuana in Colorado, a growing number of young children have been treated for accidentally eating marijuana-laced cookies and candies, according to a new study by medicos from the University of Colorado.

The study, published in JAMA Pediatrics, looked at numbers of unintentional ingestions in patients under the age of 12 before and after medical marijuana laws were relaxed in the state in 2009. Fourteen children were treated at Colorado Children's Hospital in two years after a 2009 federal policy change which meant federal authorities would not prosecute legal users.

The health scares incurred by these children were mostly mild, but parents should know about potential risks and keep the products out of reach, said lead author Dr. George Sam Wang, an emergency room physician at the hospital.

"We are seeing increases in exposure to marijuana in young pediatric patients, and they have more severe symptoms than we typically associate with marijuana," said lead researcher Dr. George Sam Wang, a medical toxicology fellow at the Rocky Mountain Poison and Drug Center in Denver.

Some of the symptoms recorded included unusual drowsiness, unstable balance to more serious cases in which one 5-year-old boy had trouble breathing. Eight children were hospitalized, two in the intensive care unit, though all recovered within a few days, Wang said. By contrast, in four years preceding the policy change, the Denver-area hospital had no such cases.

Children recover quickly in most cases, Wang said. "They don't need more than a day or two of hospitalization," he said. "There were no deaths or lasting side effects."

Wang has suggested the way to prevent these accidents from happening in the futures is to sell the medical marijuana cookies or candy in child resistant packaging. It has since been passed by the Colorado Department of Revenue which will now require child proof packaging for marijuana products by July 1.

Before Sept. 30, 2009, none of those possible poisonings was attributed to marijuana. "Because of a perceived stigma associated with medical marijuana, families may be reluctant to report its use to health care providers," they wrote in the study.

Eighteen states and Washington, D.C., allow medical marijuana, though it remains illegal under federal law. Last year, Colorado and Washington State legalized adult possession of small amounts of nonmedical marijuana.