Video: Dr. Nancy looks at cell phone cancer study

  1. Closed captioning of: Dr. Nancy looks at cell phone cancer study

    >>> back now at 7:45. do cell phones cause cancer? that question has been asked for decades now, and the latest answer from the world health organization is, quote, possibly. dr. nancy snyderman is nbc's chief medical editor.

    >> hi, ann.

    >> possibly. what does the world health organization mean by that?

    >> they put a stamp on let's get more evidence. 31 doctors from 14 countries said, we have looked at everything and there is no study that shows a link between cell phones and the brain tumors that kill. there was a study where they took people with brain tumors and said, okay, tell us how much you used your cell phone . not a great study. everybody recognizes the flaws, but it's the one thing people go, oh, well, maybe, possibly, perhaps. all these terms have been thrown out. the looming question is conventional wisdom would say, if you put a trans mitter next to hur heayour head, can it hurt you. some people say, well, it can't be good for you so it must be bad. there is no evidence that cell phones cause cancer. so they said, okay, let's kick the can forward, gather data and put it to rest.

    >> however the cell phone industry group called ctia issued a statement saying, quote, this classification does not mean cell phones cause cancer and noted that the same score has been given to pickled vegetables and coffee.

    >> the category where they put cell phones has talcum powder, pickled vegetables . so i think it's prudent to recognize that 5 billion people use cell phones . we have seen a huge explosion in the technology but no increase in the tumors. there is no correlation yet. the counter argument will be, maybe we have to wait 20, 30 years. well, perhaps. i want to underscore again there is no cause and effect . i have heard a lot of media organizations over the last 24 hours say there is a new study out. this is almost a call to action to keep gathering data.

    >> it's a review of studies, not new research. meantime, there's been a scientific consensus that children's brains are more susceptible to radiation because, as their skulls are thinner, nervous systems are still developing, what should -- what's the takeaway? should we limit use? what's your bottom line?

    >> kids' brains, bodies, every part of them grows fast. that's why we are always more worried about their environmental links to anything. just because they are using cell phones which is a microwave technology doesn't mean they are more at risk. we'll have to follow them further out. but for people, if you are scared, and there is no cause and effect yet, but if you're scared get it away from your head. but frankly, more people die using cell phones while texting and talking while driving than anything else right now. that's the take-home, i think that supercedes everything else.

    >> all right. thank you so much. dr. nancy snyderman . still

updated 5/31/2011 12:55:11 PM ET 2011-05-31T16:55:11

An international panel of experts says cellphones are possibly carcinogenic to humans after reviewing details from dozens of published studies.

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The statement was issued in Lyon, France, on Tuesday by the International Agency for Research on Cancer after a weeklong meeting of experts. They reviewed possible links between cancer and the type of electromagnetic radiation found in cellphones, microwaves and radar.

The agency is the cancer arm of the World Health Organization and the assessment now goes to WHO and national health agencies for possible guidance on cellphone use.

The group classified cellphones in category 2B, meaning they are possibly carcinogenic to humans. Other substances in that category include the pesticide DDT and gasoline engine exhaust.

Last year, results of a large study found no clear link between cellphones and cancer. But some advocacy groups contend the study raised serious concerns because it showed a hint of a possible connection between very heavy phone use and glioma, a rare but often deadly form of brain tumor. However, the numbers in that subgroup weren't sufficient to make the case.

The study was controversial because it began with people who already had cancer and asked them to recall how often they used their cellphones more than a decade ago.

In about 30 other studies done in Europe, New Zealand and the U.S., patients with brain tumors have not reported using their cellphones more often than unaffected people.

Because cellphones are so popular, it may be impossible for experts to compare cellphone users who develop brain tumors with people who don't use the devices. According to a survey last year, the number of cellphone subscribers worldwide has hit 5 billion, or nearly three-quarters of the global population.

People's cellphone habits have also changed dramatically since the first studies began years ago and it's unclear if the results of previous research would still apply today.

Since many cancerous tumors take decades to develop, experts say it's impossible to conclude cellphones have no long-term health risks. The studies conducted so far haven't tracked people for longer than about a decade.

Cellphones send signals to nearby towers via radio frequency waves, a form of energy similar to FM radio waves and microwaves. But the radiation produced by cellphones cannot directly damage DNA and is different from stronger types of radiation like X-rays or ultraviolet light. At very high levels, radio frequency waves from cellphones can heat up body tissue, but that is not believed to damage human cells.

According to Cancer Research U.K., the only health danger firmly connected to cellphones is a higher risk of car accidents. The group recommends children under 16 only use cellphones for essential calls because their brains and nervous systems are still developing.

Also, a recent U.S. National Institutes of Health study found that cellphone use can speed up brain activity, but it is unknown whether that has any dangerous health effects.

Copyright 2011 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

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