VANCOUVER - Vancouver's top doctor is defending the city's decision to ban edible pot products such as brownies and cookies, pointing to data that shows child poisonings have skyrocketed by 600 per cent in U.S. states where marijuana is legal.

Lawmakers south of the border have grappled with how to regulate the products. In Washington, nearly half of marijuana poisoning calls last year involved children, while Colorado only recently introduced stricter requirements for packaging, potency and contents.

Dr. Patricia Daly, Vancouver Coastal Health chief medical officer, said the city looked closely at the experiences of U.S. states before banning edible marijuana from stores.

"The concern is the marketing and retail sale of products that look exactly like candies and baked goods, and the poisonings that we know might occur in children," she said. "This is a really early warning signal in the United States. We don't want to see that happen here."

Vancouver city council voted on Wednesday to impose regulations on medical marijuana dispensaries, institute a licence fee and enforce strict location requirements. Edible pot products will now be banned from stores, sparking criticism from advocates who say the move violates a recent Supreme Court decision.

Daly pointed to a recent study in Clinical Pediatrics, which found that the rate of marijuana poisonings among children five years of age and younger has increased by 610 per cent between 2006 and 2013 in states that legalized medical marijuana before 2000.

She said childproof containers and labelling has not prevented such poisonings, which can cause kids to stop breathing, suffer seizures and even become comatose.

In Washington, labels on pot products can't use cartoon characters or bright colours, and each standardized 10-milligram serving of THC must be marked on the package. Edibles are limited to products that have a long shelf life, such as brownies, cookies and candies.

Still, Dr. Alexander Garrard of the Washington Poison Centre said calls about marijuana poisonings caused by edibles have tripled in the last decade. There were 245 calls last year, of which 108 were children, he said.

"I think what Vancouver has done is very forward. Some people would say it's maybe a little bit radical. But that's what we're seeing — the majority of our cases are on edibles."

In Colorado, two suicides and a murder committed by people who consumed edible pot products have grabbed headlines in the past two years. New regulations introduced in February require more explicit warnings and THC contents on labels, and provide incentives for companies to produce lower-potency products.

The Supreme Court of Canada ruled earlier this month that patients have the right to consume pot in edible forms. While packaged edibles are now banned from Vancouver stores, consumers will still be able to buy oils, tinctures and capsules to make their own food.

But Micheal Vonn, director of the British Columbia Civil Liberties Association, said the city's ban amounts to "second-class citizenship" for medical marijuana patients.

"Nobody asks you to go home and make your own Advil," she said.

"The IKEA model of 'You can assemble these parts at home' is not even feasible for all kinds of patients: those in long-term care, those in hospitals, those in single-room occupancy hotels without access to kitchens."

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News from © The Canadian Press, 2015