Ontario is slow to launch a public education campaign warning parents about the dangers of marijuana to children, which include the risk associated with second-hand pot smoke, the Pediatricians Alliance of Ontario warned Friday.

“A lot more children are going to be exposed . . . . They are the most at risk of harm. Their brains are still developing,” said Dr. Hirotaka Yamashiro.

“Ontario is not ready to deal with the risks.”

Health Minister Eric Hoskins, a physician, has said a public education campaign is being prepared for all age groups to make everyone aware of the dangers.

“There’s strong evidence that the brain continues to develop up until roughly the age of 25 and evidence that cannabis use can negatively impact that,” he told reporters earlier this year.

With legalization looming next July across Canada, this province needs to move more quickly, Dr. Sharon Burey, a behavioural pediatrician from Windsor, said in a news conference at Queen’s Park.

“We’re already starting too late,” said Burey, who added that marijuana use can cause changes to the brain, leading to poor performance in school, higher incidence of depression, anxiety and mental illness, and serve as a gateway for teens to smoking tobacco and the consumption of other drugs.

“We are gravely worried about what is going to happen to them when more of their parents smoke marijuana.”

The Pediatricians Alliance called on the government to fund research on the impact of marijuana use on families and children after pot is legalized for Ontarians 19 and older. There is no research now on the long-term effects of acute marijuana exposure in children.

“There are a lot of unknowns,” said Yamashiro.

The alliance cited statistics from Children’s Hospital Colorado, which found a four-fold “spike” in marijuana-related emergency room visits when recreational cannabis became legal in that state in 2014, compared with the number 10 years earlier.

Ontario recently introduced legislation detailing how marijuana will be sold in government-controlled stores.