Fourteen kids were treated at one Colorado emergency room for accidentally ingesting marijuana after the drug became legal for medical use there in late 2009, according to a new study.

In comparison, no children seen for a possible accidental poisoning had pot in their system in the four years before the change in laws, researchers looking back at ER records found.

"These products are now commercially available and have high amounts of THC in them," said Dr. George Wang, who led the new study at Rocky Mountain Poison and Drug Center in Denver.

Medical marijuana is now legal in 18 states and Washington, D.C. Colorado dispensaries sell baked goods, candies and soft drinks made with pot for people with cancer, HIV and severe pain, for example.

Last year, Colorado and Washington State voted to make small amounts of the drug legal for recreational use, as well.

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