A young girl with a cellphone pressed to her ear can't feel the plume of radio frequencies penetrating her brain.

But it's there. And like any child, her thinner skull, growing brain and developing nervous system make her more vulnerable than adults to the interaction of wireless signals with the body.

The potential long-term impact of that interaction remains a scientific mystery that may not be answered for decades.

It's an uncertainty that isn't stopping some wireless companies in North America from aggressively targeting children with an array of cartoonish phones featuring the images of Barbie and Mickey Mouse or video clips of Bugs Bunny.

Walt Disney Co., which backed off plans to sell cartoon character-branded cellphones in 2000 amid public concerns about potential risks for young bodies, snagged headlines across North America this week after announcing a new line of cellphones aimed at children as young as 8. Parents like the idea of being able to stay in touch with their children at all times. Pre-teens see the phones as status symbols. And the wireless industry, facing slowing sales to adults, sees children as a lucrative, untapped market.

Some scientists say those pressures are triggering a leap into the unknown.

Children are using cellphones at a younger age than any previous generation. They'll be exposed for more years — and spend more time each day with the phones pressed to their heads — than anyone before.

And some scientists are raising serious questions about biological changes caused by cellphone frequencies. The worry is that these changes could lead to physiological problems ranging from headaches to cancer to degenerative brain diseases — problems that could take many years to prove or disprove.

Other scientists dismiss such concerns, pointing to research that shows no reason for worry.

Health Canada acknowledges unease about potential cellphone effects in internal documents obtained by the Toronto Star. But publicly, it has remained silent.

In contrast, health officials and experts in several European countries have issued public warnings to parents urging caution about kids and cellphones, backed by a growing body of scientists who fear that if health effects are eventually shown, the results could be disastrous.

"There are rational reasons to implicate a potential risk," says Dr. Ab Guha, a prominent Toronto neurosurgeon and co-director of brain tumour research at the Hospital for Sick Children.

"If we can avoid finding out 15 or 20 years later that we have a whole bunch of adults that have developed a variety of tumours, it makes good sense (to urge caution)."

Many scientists point to public health tragedies such as tobacco and asbestos, deadly threats that were only proven after generations of research.

"It disturbs me that kids are the marketing target for devices that are dressed up to look as innocuous and friendly as possible, and yet may have longer-term health implications attached to them that we're not fully aware of," says Dr. Sheela Basrur, Ontario's chief medical officer of health and mother of a 14-year-old daughter whose repeated requests for a cellphone have been denied.

"It falls on government and industry to provide this information in a readily accessible, easily understood fashion so you don't need a post-doctorate degree in radiation physics to realize that the jury is out."

The $120 billion North American industry is quick to dismiss any concerns, insisting that science has not drawn a conclusive link between the devices and health impacts.

"There are no indications that there are demonstrated public health risks in using cellphones," says Peter Barnes, president and CEO of the Canadian Wireless Telecommunications Association.

"You can never test every final, last, infinite possibility out there. The more there are studies made, the more certainty there can be to the statement of no demonstrated public health risk."

Barnes' comments were echoed by the U.S. Cellular Telecommunications and Internet Association.

The issue is less clear-cut inside Health Canada.

Seven years worth of internal Health Canada documents, obtained through access to information requests, reveal concerns about cellphone frequencies and potential — but unproven — links to "childhood leukemia, brain and other cancers of the head and neck, memory problems, stress and migraine/neurological ailment."

One document plainly states: "Children are at the highest risk from (radio frequency) exposures."

Yet Canadians who visit the agency's website are simply instructed to decide for themselves whether they can live with the "possibility of an unknown risk from cellphone use."

Many experts and health authorities in Europe see it differently.

In 2000, the German Academy of Paediatrics warned parents to limit their children's calls. That message was repeated a year later by the head of Germany's radiation protection agency, which said links to leukemia and eye cancer couldn't be ruled out.
Seven French scientists released an in-depth report in 2001 urging parents to restrict their children's cellphone use.
In 2001, a committee with the Russian radiation protection bureau advised pregnant women and children under the age of 16 to avoid cellphone use.
British health officials have arguably been the most proactive, twice urging the nation's wireless industry to refrain from promoting cellphones to children and publicly discouraging children from using them for "non-essential" calls.
There have been no such public cautions in Canada or the U.S.

Dr. Robert Bradley, head of the radiation protection department of Health Canada, says his agency has issued no public statements about risks to children from cellphones.

"We don't have a particular piece of advice on the (agency's) website and it's one I think we should be developing."

Health Canada has maintained a quiet public approach despite internal concerns dating back to at least the late 1990s.

A 1998 memo cites "significant evidence" that frequencies similar to those emitted by cellphones could allow carcinogens and other toxins to seep into the brain. And recommendations for aggressive research funding in this area — including studies aimed at children — have been ignored, documents show.

"If there are health risks, even if small, the economic impact in terms of health-care costs is expected to be great because of the prevalence of (radio frequency) exposure in our daily lives," says a 1999 internal Health Canada document.

Another document from the same year concedes that Canada "lags significantly behind efforts (of) other G-7 countries" on research into radio frequency effects and says "Inspection and enforcement is very weak or non-existent."

The document called for a 10-year, $11.5 million research program to "allow relevant risk management options to be proposed."

That research funding never materialized.

A year later, another Health Canada proposal argued that studying cellphone effects on children's brains and eyes was necessary for "risk assessment," would help reduce "the possibility that acute health effects will develop in children" and would provide the knowledge needed to ensure that the department's regulatory approach would "adequately protect children."

The calculated cost for such research was $700,000 a year.

It never came.

Today, the agency's financial commitment to cellphone emissions research is $150,000 a year — the same as it was five years ago.

That's a drop in the bucket compared to many European countries. The British, for example, have devoted $15 million (U.S.) over four years and are in the process of earmarking more.

Most studies over the past five years have been done in Europe. And while the research offers no clear answers, it's increasingly certain that wireless radio signals can cause biological effects — such as breaks in rat and human DNA, or nerve cell damage in animal brains — that potentially could be precursors to health effects.

Nearly 60 per cent of the more than 250 studies looking at the health effects of cellphone frequencies have shown some form of biological effect, according to an analysis by Dr. Henry Lai, a top researcher of the subject at the University of Washington in Seattle.

"There's a cause for concern," says Lai. "The radiation is not as safe as the cellphone industry asserts."

He says some effects, including potential sperm cell DNA damage found in a recent Australian study, are "likely to be health hazardous."

Dr. Michael Repacholi, who heads the radiation research program at the World Health Organization, takes a different view, arguing that it's normal to see small biological effects in lab experiments.

"If you start getting effects that are going to damage DNA ... that's something that could lead to a consequence. But most of the biological effects that are reported are well within the range of normal compensation of the body."

Dr. Mary McBride, senior scientist in cancer control research at the B.C. Cancer Agency, agrees biological effects aren't necessarily cause for concern.

"There are many examples of biological effects that are neutral and positive in terms of health, so there's no reason to presuppose that because there is a biological effect that that should raise a red flag in itself."

While the scientific community remains divided on the link between cell signals and potential health risks, there's growing concern about the lack of research related to children.

Computer image modeling comparing the heads of adults and children has shown radiation penetrates far more deeply into young skulls, resulting in greater exposure to potentially harmful radio waves.

As the youngest users of this technology, today's children will be exposed more than any other generation to a steady stream of wireless signals. Market researchers predict 10 per cent of Canadians aged 8 to 11 will have their own cellphones by the end of this year, a number expected to quadruple by 2008.

Linnea Busby recently got a cellphone for her 11th birthday after a year-and-a-half of asking her parents.

She uses it to chat with her friends, who also have their own cellphones, and check in with family.

"I like the idea of her having a phone for security reasons," says Martin Busby, Linnea's father. "The investment is well worth knowing I can be in touch with her. And it's a status thing for her. If it gets to the point where it's stuck to her ear all the time, it would concern me. It concerns me a little bit. But she knows it's not a toy."

Concern about cellphone exposure is one of the reasons Adam Kucharski took back the cellphone he gave his son Alex two years ago. The 13-year-old Richmond Hill student used to carry the phone with him everywhere. His parents cancelled his plan three months ago.

"I think they're overused," says Kucharski, a computer specialist. "And in the back of my mind I have concerns about the (radio frequencies). It's better to be cautious. Frequencies are getting higher and that has an impact."

In the absence of any clear advice from Health Canada, the industry has become the de facto voice on wireless health effects.

And its message is clear.

On its website, the Canadian cellphone association claims that "overwhelming evidence in the scientific community ... supports the conclusion that there is no demonstrated public health risk."

It also says government agencies "support that wireless telephones are not a health risk."

But Health Canada officials say they are uncomfortable with those claims.

"That's their statement; it doesn't come from us," says Bradley. "There are still issues that need to be addressed so we can feel more comfortable with saying that ... There is no heavy, strong leaning saying, `No, absolutely, totally on the safe side,' nor the other way, saying, `Absolutely, totally bad.'"

The industry's Barnes says the difference in messages reflects the differing "roles" of industry and science.

Even though studies indicate biological effects, he says the scientific community has not informed his association of any proven health effects.

"We've also been told they want to continue studying it and we're more than willing to co-operate with them," he says.

• • •

Meanwhile, Canadian children are using cellphones in record numbers.

By next year, one in every five children aged 8 to 11 will have a wireless phone, according to forecasts from Toronto-based Solutions Research Group.

That figure is expected to balloon as campaigns rev up and wireless phones become more accepted as a replacement for "wired" phones.

Some experts have conservatively suggested that half of all pre-teens in this country will regularly use a cellphone by the end of the decade.

Adding concern is the fact that the cellphone industry is relatively young. In Canada, the industry celebrates its 20th anniversary this summer, but the phones were very much a novelty during the first decade.

It's only been in the past five to eight years that consumers have been able to enjoy unlimited evening and weekend calling, affordable monthly rates and heavily subsidized handsets. Cellphones have become an essential social and business tool for many, and this has led to a dramatic increase in the time we spend using these devices.

For example, Canadians spent an average of 262 minutes a month on their cellphones in 2002, according to a report last year from Bell Canada, which predicted that by the end of 2005 average minutes would jump to nearly 400 — a rise of 50 per cent.

Some scientists say it could take decades to determine whether this popular embrace of cellphones will affect health, particularly for adults who began using the devices as children.

U.K. officials don't want to wait until it's too late.

"At this time, we believe that the widespread use of mobile phones by children for non-essential calls should be discouraged," stated a report last year from the National Radiological Protection Board, a part of the U.K. Health Protection Agency.

"We also recommend that the mobile phone industry should refrain from promoting the use of mobile phones by children," said the report, which encouraged the government to send information leaflets to every U.K. household outlining the health aspects of mobile phone use.

Dr. Michael Clark, scientific spokesperson for the U.K. protection board, says the British are more cautious than most countries because of the Mad Cow scare during the mid-1990s that caught the government off guard.

"You could look at the BSE thing and say we weren't cautious enough in the early days," he says. "More children and younger children are using mobile phones. We felt we should re-emphasize the precautionary advice."

Canada has so far decided to steer clear of any such cautionary messages. But Bradley concedes the agency may now need to do more.

"We'll have to look at this over the next couple of months and see whether or not there is a missing piece of information for the public," he says.

Meanwhile, red flags continue to emerge as the industry matures and cellular use increases.

A study out of the Karolinska Institute in Sweden last fall found that people who used a cellphone for more than 10 years doubled their risk of developing a non-cancerous tumour of the acoustic nerve — called an acoustic neuroma — that transmits sound from the inner ear to the brain.

Though benign, the condition can lead to loss of hearing and balance. Left untreated, the slow-growing tumour can even kill.

While studies have previously documented minor health effects from cellphone signals such as headaches, sleep disorders and slowed reaction times, studies on acoustic neuromas stand out as the first major warning signs of a possible health effect.

The wireless industry downplayed the Karolinska findings as isolated. But they weren't the first.

Earlier findings out of a competing research lab at Sweden's Örebro University found increased incidence of the benign tumour among long-term cellphone users.

A follow-up study published in June reinforced that conclusion.

Dr. Louis Slesin, who has published the respected New York-based scientific newsletter Microwave News for 20 years, calls the Swedish studies a "bombshell."

"As far as I'm concerned, the acoustic neuroma data is not quite a smoking gun, but it's pretty close," Slesin told the Star. "If there are any more studies showing acoustic neuroma increases, all hell will break loose."