Toronto Public Health is advising children and teenagers to limit their exposure to cellphones until more is known about the potential health effects of the devices.

A report from the city's medical officer of health recommends children, especially pre-adolescents, only use cellphones for essential purposes, the Toronto Star reports.

Other recommendations for kids include:

• Limiting the length of cellphone calls to five or 10 minutes
• Using headsets or hands-free options whenever possible
• Using landlines whenever possible

The cellphone policy is believed to be the first of its kind in Canada, the Star reports.

The public health agency is urging caution because of a lack of research on cellphone use among children.

Loren Vanderlinden, a Toronto Public Health supervisor who authored the report, says an accumulation of studies seems to indicate that prolonged cellphone use increases the risk of certain kinds of brain tumours.

"We think it's responsible to limit children's exposure," Vanderlinden writes.

Since children have smaller heads and thinner skulls than adults, some studies show signals radiate further into children's heads than those of adults.

The Star says 61 per cent of 12- to 19-years in Canada have a cellphone, but there are no statistics for users under 12.

Industry officials have consistently and vigorously denied that radio frequencies from cellphones present any sort of health risk.

However, Toronto's health advisory follows similar precautionary policies introduced in several European countries, including the United Kingdom, France, Germany and Russia.

Health Canada has not issued any warnings about cellphone risks to children.

"Health Canada currently sees no scientific reason to consider the use of cellphones as unsafe," the federal agency wrote to the Star.