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It is very crucial that I ask whether it ``could'' and not whether it does. I do not mean to be the least controversial.

To my surprise, having read ``Physics for Future Presidents'' by Richard Muller last year, I've come across a sentence of the sort (I'm paraphrasing): cell phone radiation is way too weak to effect molecular structure, and therefore any claim about cell phone radiation causing cancer can be attributed to people blaming cell phones for their cancer.

This seems like a very strong statement! Is this a consensus among physicists that there is absolutely nothing to the claim that cell phone radiation could possibly (in any significant way) cause cancer? Is this really just being thrown around because people don't understand the physics?

To be very precise, the question is: is there a physics model that would suggest a mechanism by which cell phone radiation can cause any sort of damage that could lead to cancer?

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I recently read that one might have to consider multi photon effects and I'm absolutely not sure if this radiation is safe. On the other hand I don't want and wouldn't know how to design a test. Maybe you'll have to use big animals (like pig). –  whoplisp Jul 8 '11 at 23:12
    
The problem here are not physical considerations about phones but the biomedical considerations about human response to EM fields. And well, experiments on humans are very hard since objects are very variable, difficult to gather, live long and are hard to constrain in controlled environment. –  mbq Jul 9 '11 at 10:34
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Skeptics.SE has had a much higher-quality discussion of this topic: skeptics.stackexchange.com/questions/569/… –  Ben Crowell Jul 29 '11 at 20:49

5 Answers 5

up vote -4 down vote accepted

Having co-authored a review of the epidemiologic research*, I believe long term (approx. 10 or more years) cell phone use increases tumor risk in humans, especially gliomas, acoustic neuromas, and tumors of the parotid gland.

I agree with mbq that the effect is likely due to electromagnetic radiation (EMR) that interferes with bioelectrical processes through non-thermal mechanisms.

A cursory review (unpublished) of 116 published toxicology studies, including animal studies and human cellular studies, suggests that some cell phone carrier systems are more likely to be biologically reactive than others. Namely, systems that pulse the signal at extremely low frequencies (i.e., TDMA, GSM, and UMTS) are about three times more likely to yield statistically significant biologically reactive outcomes as compared to carriers that do not pulse the signal (i.e., CDMA and W-CDMA) (36% vs. 12%). However, when EMR is tested at higher power outputs that exceed the current legal limits for cell phones (based upon a measure called the Specific Absorption Rate), then toxic effects are more likely observed regardless of carrier. However, at these higher power outputs we cannot rule out a thermal mechanism.

  • Seung-Kwon Myung, Woong Ju, Diana D. McDonnell, Yeon Ji Lee, Gene Kazinets, Chih-Tao Cheng, and Joel M. Moskowitz. Mobile Phone Use and Risk of Tumors: A Meta-Analysis. Journal of Clinical Oncology. 20(27):5565-5572. Published online first Oct 13, 2009. Nov 20, 2009.URL: http://www.ncbi.nlm.nih.gov/pubmed/19826127
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Here is some intelligent analysis: xkcd.com/925 –  Georg Jul 15 '11 at 9:00
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This is a nice example of how junk science gets published in otherwise reputable peer-reviewed journals. There is no plausible mechanism. Animal studies do not show an effect. Human studies that get non-null results don't show a dose-response. –  Ben Crowell Jul 29 '11 at 18:52
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I have issues with this response and this paper. The nonthermal mechanism bit is barely plausible. And it strikes of homeopathy, where increasing rates leads to no observable response. –  Columbia Jul 30 '11 at 17:58
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This is not responsive to the question, which is "Is there a physics model that would suggest a mechanism...that could lead to cancer". –  Mark Beadles Jul 20 '12 at 15:49
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-1: I think that the paper that is linked is junk--- there is no way to extract effects from 10 year cell phone use which are decoupled from all sorts of other factors. You would do better to compare 10 year hands-free. –  Ron Maimon Jul 20 '12 at 18:59

No, cell phone use does not cause cancer. We know it doesn't cause cancer because:

  1. There is no plausible mechanism.
  2. Animal studies show no effect.
  3. Human studies that get non-null results don't show a dose-response.

Doing these cell-phone studies with human subjects makes as much sense as doing studies to figure out whether I can cause my neighbors to get cancer by thinking evil thoughts about them. In both cases, there is no remotely plausible physical mechanism for the direct effect as postulated. The only reason to do the cell-phone study and not to do the evil-thoughts study is that the former appeals deeply to people's folk beliefs, which have been built up from decades of movies and comic books where "radiation" causes magical effects.

Some studies with human subjects give positive results and some give null results. This should not surprise us. The studies are measuring the relative sizes of their random and systematic errors. In the studies where they succeed in getting their random errors down to a smaller level than their systematic errors, they will measure either a positive or a negative correlation with cancer. In the ones where they succeed in getting their systematic errors down to a smaller level than their random errors, they will get a null result.

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+1, because this is the reason one thinks there is no connection, but I don't think you give a fair analysis of the reason to suspect a connection. Macromolecules can in theory respond to low frequency electromagnetic stimuli, they have delocalized electrons, and cells are even bigger. The effect on the complex tangle of macromolecules is not clear, but it is best estimated as null from the epidemological data (no increased cancer). You can't say it is null a-priori, however. You need the data. –  Ron Maimon Jul 20 '12 at 18:56
    
And are studies that show a (small) negative correlation less likely to be published, introducing a positive bias? –  Keith Thompson Jul 25 '12 at 20:13

It could due to multi-photon effects. It's already known that cell phones cause changes to brain activity. This was widely reported in the news. For example see "Cell Phone Study: Cell Ups Brain Activity". As of now, this is an unknown effect. So it might be associated with something that causes cancer.

(I'm not worrying.)

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Thanks! Where can I read about multi-photon effects? (or if it's easy: what is it?) –  Wesley Jul 9 '11 at 21:00
    
Multi-photon effects from a classical device? –  Alex 'qubeat' Jul 9 '11 at 23:03
    
When you talk about "single-photon" stuff you need quantum mechanics. Classical mechanics is restricted to the "multi-photon" domain. Example: Your microwave oven uses huge numbers of microwave frequency photons to heat your food. The fact that your food gets hot is a "multi-photon" effect. Putting your head in a microwave could kill you by overheating but it shouldn't cause cancer. On the other hand, no one has run the experiment. Maybe small amounts of localized heating causes cancer. Not by direct genetic change, but instead by, for example, harming the body's natural anti-cancer system. –  Carl Brannen Jul 10 '11 at 4:38
    
Term "multiphoton" usually have other meaning so your terminology was not clear for me. Amount of photons does not matter much, laser may emit even more photons than some classical source. –  Alex 'qubeat' Jul 10 '11 at 10:43
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More actual example: NIST wrote about hazard of 20 mW laser pointer, but 100W classical source is not considered as something dangerous, yet it is 5000 more. So accurate consideration of difference between quantum and classical sources may be important. –  Alex 'qubeat' Jul 10 '11 at 11:00

This wiki article covers most bases.

In conclusion, the connection to cancer is unclear from controlled studies. There is some surface heat that can be generated when next to the head, of the order of 2 watts but not clear how bad that is. Sunbathing hatless heats by many more watts (1300/m^2). Cancer of the skin has been connected with the sun due to ultraviolet radiation ( cell phones are microwave range), but not the head.

If I were a man I would avoid hanging a cell phone next to the family jewels, because heat is deleterious to fertility:).

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Shadow of brain is about 10cm x 10cm so 1300W/m^2 gives 13 W over the whole brain. But apparently the cell phone heat is more localized. (Still, I do not believe that cell phones increase the cancer rate, just saying that it hasn't yet been scientifically eliminated as a possibility. I'd like to see it eliminated.) –  Carl Brannen Jul 11 '11 at 5:42
    
@Carl :) . Yes, but a lot of people sunbathe a lot and integrated heat would be much larger than any cell phone use. Cancer from the sun is associated with skin.Do you think it would not have been found and correlated if it generated brain cancers since so much study has gone into it? –  anna v Jul 11 '11 at 5:50
    
I was just correcting your comparison between 2 and 1300. The comparison fails because sun and phones apply different frequencies. But it raises the question, "if you apply sunlight to someone's head, does it cause the same sort of differences seen in the recent cell phone brain study?" Unfortunately, a positive answer to that question still wouldn't absolve cell phones. Proving a negative is difficult. –  Carl Brannen Jul 11 '11 at 5:55
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There is a study that concludes that heavy phone use might have long term effects: oxfordjournals.org/our_journals/ije/press_releases/freepdf/…;. They don't want to state that their study proves these effects, though. –  whoplisp Jul 11 '11 at 17:47

Generally ,I do not think cell phone use significantly increase the risk of getting cancer , However, I think that cell phone use have temporary effect on cognitive function because EMFs even if it is non-ionizing can have interactions with biological systems especially the brain which is electrically and metabolically very active .

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+1, because one doesn't know for certain absent data, whether the brain is sensitive to low frequency EM. Birds detect zero frequency EM, in the Earth's magnetic field. That doesn't mean it causes cancer, but it could interact with brain function in a nontrivial way. –  Ron Maimon Jul 20 '12 at 19:00

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