Scientists split on cancer risk, tissue damage
Planning on buying a cell phone for a loved one this Christmas? You’re not alone.
Worried about those sporadic reports linking their use with health risks? You’re not alone there, either.
But you can rest easy. What should be the most definitive science yet is on the way. And you’ll only have to wait five years.
For those consumers concerned about the radiation emitted by their cell phones, the news is not exactly reassuring.
“I’d heard they can cause tumours and stuff like that,” says Damien Martin of Ajax.
The 25-year-old financial analyst isn’t sure he believes some of the more alarming stories he’s read. But he also isn’t sure he embraces the industry position that everything’s hunky-dory.
“I have my doubts,” he says.
That’s understandable. While there’s a growing number of studies showing a clear link between cell phone use while driving and car accidents, the data on other health risks is considerably muddier.
Some recent studies have suggested that even low doses of the kind of radio frequency energy emitted by such phones may cause subtle changes at the cellular level. There’s no evidence that’s bad for you, but – at the moment – we really don’t know for sure.
It’s that “dunno” factor that will result, later this month, in health warnings included with all new cell phones sold in the United Kingdom. The leaflets will recommend that children limit their use of the phones. But it won’t suggest there’s a direct health risk – only that the science is incomplete.
So. What’s a concerned consumer to make of all this?
Depends on whom you ask.
“This issue has been very well researched,” says epidemiologist Dr. Daniel Krewski, who was a member of an expert panel assembled by the Royal Society of Canada to study the issue. He’s also chair of the Wireless Information Resource Centre, an industry-established (but independent) body created to provide the public with objective scientific information about wireless communications and health. His conclusion?
`None of the evidence provides any clear indications of adverse health effects.’
– Dr. Daniel Krewski
`We have evidence of genetic damage (and) of an increase in the risk of tumours.’
– Dr. George Carlo
“None of the evidence provides any clear indications of adverse health effects,” he says.
Whew. That feels much better. Especially when you consider the near-exponential growth in sales. In a mere decade, the number of Canadians who’ve joined the wireless ranks has grown from 525,000 to 8.9 million – with two million of those signing on this year.
The relief fades, however, when you start talking to Dr. George Carlo. The Washington-based epidemiologist and lawyer has also read pretty much all the science out there. In fact, he’s the guy the U.S. Cellular Telephone Industry Association hired to oversee a six-year, arm’s-length, $27 million (U.S.) research program. And, unlike Krewski, he’s concerned.
“We already have enough data to know that there are biological effects from radio frequency radiation. We have evidence of genetic damage, we have evidence of an increase in the risk of tumours,” he says. “So that’s enough right there to say that there’s something going on – and it doesn’t look good.”
Depending on how you interpret (and select) the available data, both scientists are correct. There are plenty of studies indicating that the radio frequencies emitted by wireless communications devices pose no risk; a smaller number of studies, however, raise questions.
Carlo believes the industry “cherry-picks” – embracing research that mirrors its interests while downplaying or dismissing that which does not. The counter-argument is that Carlo picks some worrisome cherries of his own, focusing on the relatively few studies that indicate potential health risks.
“There’s . . . information to support virtually anybody’s argument,” he says. “And that’s the phenomenon that you’re seeing: There’s enough that’s been done for the industry to take comfort; there’s also enough in what’s been done for others who believe that there are problems, to use that to say that there are problems. And it’s unfortunate that the consumers are caught in the middle.”
`There really is no hard data anywhere to support the idea that cell phones have a relationship to brain tumours.’
– Margaret Young
Brain Tumour Foundation of Canada
Cell phones and cancer. The words were juxtaposed in headlines around the globe back in 1993, after an episode of CNN’s Larry King Live.
The guest was a Florida widower by the name of David Reynard. His 33-year-old wife had died of brain cancer; a tumour Reynard said was located precisely where she held the phone. He was suing the manufacturer. (He lost.)
The fallout from that show was enormous. Investors dumped shares in wireless stocks. More lawsuits were filed (also unsuccessful). The U.S. Food and Drug Administration and the National Cancer Institute advised shaken consumers they could consider limiting the time they spent on cell phones. People were scared.
The industry, in an effort to quell a public relations nightmare and reassure consumers, responded by funding the massive research program chaired by Carlo. The publicity – and potential health implications – spurred many other studies and expert reviews of the data. The hope was that the question of cell phones and health would be answered once and for all.
It has not been. Not totally. Although what scientists call “the balance of evidence” doesn’t indicate there’s a problem, even the industry agrees there’s still more work to be done.
“The industry position is twofold: first, there are no demonstrated public health risks,” says Peter Barnes, president and chief executive officer of the Canadian Wireless Telecommunications Association, the group representing wireless carriers and manufacturers. “But the second component is that there is need for continuing and additional research.”
On that, there is widespread agreement. Whether it’s Health Canada, the Royal Society expert panel, the manufacturers or Carlo, there is a consensus that we must clearly answer some of the unknowns.
“The single most important recommendation (of the Royal Society panel) was for a large-scale study of people using cellular telephones and potential cancer risk,” says Krewski. In fact, Canada will soon be participating in a 13-nation World Health Organization study that will directly examine the health effects of exposure to energy fields – including those generated by cell phones.
“It’ll take about five years, it’ll be the largest study of its kind ever conducted,” says Krewski. “And at the end of that five-year period we should have direct evidence on whether or not cellular telephones pose any kind of health risk.”
Critics like Carlo argue five years is a long time to wait.
“More research over the next five years does absolutely nothing for consumers today – I can’t stress that enough,” he says. “More research is part of what needs to be done. But the hard question is: What do we do today, when the science is uncertain?”
In theory, any potential health risk would be the result of low levels of radiation being absorbed by body tissue. We know that approximately half of a cell phone’s radiation penetrates about a centimetre into the head and hands of the user when the phone is held close to the ear.
While that may sound creepy, radio frequency (RF) energy – though a type of radiation – has nothing in common with x-rays. It does not cause radioactivity in the body, nor has it been shown to break chemical bonds. (Although one well-publicized U.S. study indicated genetic damage, other scientists have not confirmed the findings.)
What’s very clear is that at certain frequencies and power levels, RF energy can heat tissue: that’s how your microwave works. That’s also why Health Canada has a guideline designed to protect Canadians from RF energy that could cause these thermal effects.
It’s called Safety Code 6. It limits the energy emitted by cell phones (and absorbed by human tissue) to a rate well below that believed to cause any adverse health effects.
“Nobody questions the limits today – (no one questions) whether they’re safe levels,” says Peter Minaki, manager for regulatory affairs and standardization for Ericsson Canada and an engineer. “That (Safety Code 6) is an established figure.”
Questions have been raised, however, over non-thermal effects: subtle biological changes that can occur even when levels of energy absorbed do not exceed Safety Code 6. For instance, research indicates that the rate at which certain molecules move between cell membranes appears to change.
“There is a growing body of scientific evidence,” states the Royal Society’s expert panel report, “which suggests that exposure to RF fields at intensities far less than levels required to produce measurable heating can cause effects in cells and tissues.”
One of the unknowns is whether or not these non-thermal effects can cause problems. Krewski doesn’t think so – but can’t say for sure until the science is in.
“These biological effects, which are of no known health significance, probably really should be clarified to strengthen the assurances of safety that we currently have,” he says.
In the U.K., an expert panel similar to Krewski’s also noted these biological effects. And while it stated there is no indication of any resulting health risk, it did recommend that children – whose brains and skulls are still developing – be discouraged from making non-essential calls via cell phones. It also called for a “precautionary approach . . . until more detailed and scientifically robust information becomes available.”
The Brain Tumour Foundation of Canada echoes the U.K. report’s somewhat cautious tone.
“There really is no hard data anywhere to support the idea that cell phones have a relationship to brain tumours,” says Margaret Young, the foundation’s director of development. “But of course, in the meantime, it’s wise not to use cell phones excessively.”
But what about Carlo’s assertion of a connection between tumours and cell phone use?
A peer-reviewed Swedish study published in May focused on 209 people with recently diagnosed brain tumours. It then compared their cell phone use with the wireless habits of a group of healthy folks. It found a correlation between the location of the tumours and the side of the head on which the phone was usually held. The report stated, however, that “this result was based on a low number of exposed subjects and must be interpreted with caution.” It was based on just 13 of the patients.
`There’s . . . information to support virtually anybody’s argument . . . it’s unfortunate that the consumers are caught in the middle.’
– Dr. George Carlo
But the study did highlight an important fact. Despite the large body of evidence from which we’ve extrapolated assurances of safety, very little work has been done on real people using real cell phones in the real world. As Canada’s Wireless Information Resource Centre points out, “there is a paucity of research examining their impact on human health.”
That, in a nutshell, is why critics like Carlo are concerned. Even an exceedingly slight risk, he argues, could have vast implications.
“This is the fastest growing technology in the history of civilization . . . Around the world, there are half a billion people exposed to a product that we are not sure is safe,” he says.
But, say other scientists, regulatory bodies and the industry, we’re sure enough.
“What I take comfort in is that the global and national organizations which have looked at a broad range of studies, including Dr. Carlo’s, have come to the same conclusion. And that is that there’s no demonstrated public health risk,” says Barnes.
Semantically, such a statement is not the equivalent of saying cell phones are perfectly safe. But science can’t make such promises.
“Absolute safety is something we probably can’t guarantee for virtually anything in life,” says Krewski, who – incidentally – does use a cell phone. His only precaution is to fully extend the antenna to keep the most intense spot of energy slightly away from his head. Carlo opts for using a headset and microphone, holding the phone itself away from his body.
Damien Martin, the cell phone user out in Ajax, is also taking precautions. He’s purchased something called a Wave Shield, a gizmo designed to reduce the radiation that reaches his head.
“I hope it’s protecting me,” he says of the $29.95 device. “Whether it is or not, I don’t know.”
Just as we don’t know – not for certain – whether he even needs it.