Toronto's department of public health is advising teenagers and young children to limit their use of cellphones to avoid potential health risks.

The advisory — believed to be the first of its kind in Canada — warns that because of possible side effects from radio frequencies, children under eight should only use a cellphone in emergencies and teenagers should limit calls to less than 10 minutes.

"Teach them the ways to use a cellphone responsibly — to make shorter calls, to use other modes of communication; if it's possible, use a landline," said Loren Vanderlinden, a health department supervisor and the report's author.

In an interview with the Toronto Star, Vanderlinden said scientists were dismissive of any risk years ago. But with more studies, she said, a pattern is emerging that suggests people who have used their cellphones for a long period of time are at greater risk of certain kinds of brain tumours.

Eight years ago, a government inquiry in Britain concluded cellphones shouldn't be marketed to children under 16 because so little was known about the long-term health risks.

But according to Health Canada, there is no firm evidence that cellphones pose health risks.

"Health Canada currently sees no scientific reason to consider the use of cellphones as unsafe," the agency wrote. "Health Canada is basing this conclusion upon the bulk of scientific evidence from …studies that have been carried out worldwide, including at our laboratory."

The Canadian Wireless Telecommunications Association, which represents Canada's cellphone industry, also said there is no need for anyone, including children, to change their cellphone habits.

"The state of the science right now from leading health agencies, including the World Health Organization, is that cell phone use — as set out in the guidelines — is that these devices are safe," said Marc Choma, a spokesman for the organization. "And that is the state of the science worldwide."