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Cell Phones and Cancer

by Michael Shermer, Dec 07 2010

Ever since the publication of physicist Dr. Bernard Leikind’s article in Skeptic (see eSkeptic for June 9, 2010) and my subsequent column in Scientific American in which I cited Leikind’s arguments (both of which were skeptical of claims that cell phone use causes brain cancer), we have been inundated with letters disputing our skepticism. The letters come in a variety of flavors, so what follows are Dr. Leikind’s responses to the critics that he identifies by their email names. My own response to critics will appear in the next issue of Scientific American, so in the meantime I defer to Dr. Leikind’s responses below, as well as to the SkepDoc Harriet Hall, M.D. along with oncologist Dr. David Gorski, both of whom blog at, which covers the ongoing controversy over cell phones and cancer.

For example, when I queried her on my critics, Dr. Hall responded to me:

I agree that it is premature to say that cell phones “can’t possibly” cause cancer, although Leikind is correct to say physics shows they can’t possibly do it by the mechanisms that have been commonly proposed. The fact remains: there is no good evidence that cell phones do cause cancer. And so far I’m not convinced by the proposed mechanisms by which they might cause cancer. The radiation/mutation and tissue heating explanations have pretty well been debunked. I’m going to continue to think that cell phones don’t cause cancer — and that there is a high probability that the kind of radiation they emit “can’t” cause cancer — until I see something much more convincing in the way of evidence. If they do somehow cause cancer, studies to date have established that any effect can’t be a very large one. Any potential cancer risk pales against the high risk of accidents from using them while driving, and against the convenience and safety effects of having instant communication.

And I asked Dr. Gorski as well, and he responded to me thusly (with links to further reading):

Basically, as I said, the article is correct in dubbing the idea that cell phone radiation causes cancer as very, very improbable, but I thought Leikind went too far in declaring it “impossible” based a priori on physics because, quite frankly, he completely ignores newer biological understanding of mechanisms of carcinogenesis. As I said in my post, I do not believe that cell phones cause cancer. I consider it highly unlikely and implausible. I do think, however, that declaring it “impossible” is premature. More reading from

And, here’s my explanation on just how complex cancer is:

Finally, Dr. Leikind sent me this wonderful general response to the critics, which I happen to agree with and will be interested in hearing from readers about this ongoing controversy:

It interests me that so many readers see “microwaves from cell phones cannot cause cancer” and understand us to be saying “there are no physiological effects from microwaves.” But our message is not that there are no physiological effects, but that we (the appropriate scientists and engineers) know exactly what the physiological effects of absorbing microwaves are. And those effects cannot cause cancer, and we know this because there are many identical but more powerful similar effects, such as exercise. No one thinks that exercise causes cancer. I also find it persuasive that no one is concerned about cell phone microwaves causing skin cancer. But the radiation is more intense in our hands, ears, and scalp than it is in brains or optic or auditory nerves, and skin cells reproduce many times more frequently than any glial brain cells, and even many more times more frequently than any neuron cells.

Dr. Leikind’s responses to the posted critiques of my and his claims follow:

GreenMind suspects that I may have ties to the cell phone industry. I use an old model Motorola RAZR V3 cell phone and pay T-Mobile about $40 per month for my cell phone service. I would be happy to earn some money from my investigation and writing about cell phones and cancer.

The precautionary principle draws passionate support from public health care professional, Dr. Martin Donohoe. In the case of cell phone microwave radiation, scientists have already done the appropriate research. We know exactly what happens when any material, including living tissue, absorbs microwave radiation. The microwave energy appears as additional shaking, jostling, rattling and rolling of the molecules. In a living human being with her powerful temperature control mechanisms functioning and her blood flowing, we know that there is no potential for microwave radiation from a cell phone to cause significant, widespread or irreparable harm. Therefore, the precautionary principle does not apply. The situation is different when someone invents a new chemical. The precautionary principle would apply to eating cell phones but not to talking on them. It would not apply to texting while driving because the harmful potential is well known.

Freedom for All and dideldum worry about power levels and heating. A cell phone emits about a watt of microwave radiation. Some of that power enters the user’s hand, ear, scalp, skull, and brain and other tissues. To produce this watt of microwave radiation, the cell phone’s electronics must convert somewhat more than a watt of power from its batteries. The excess power and all of the power that goes to operate the circuitry of the phone appears as a temperature increase in the phone. The phone may feel warm. This energy transfers to the user’s hand or ear. Some may transfer to the environment by infrared radiation or convection. This energy does not cause cancer. The temperature increase in the human brain from absorbed cell phone microwave radiation is so small that many researchers mistakenly believe that there are non-thermal effects. The temperature never reaches the various potentially harmful temperatures that Freedom cites.

GreenMind questions Dr. Shermer’s and my statement that there is no known mechanism by which cell phone microwaves might cause cancer. I claim more than that there is no known mechanism. I assert that there is no unknown mechanism.

To summarize, here is the proof. We know exactly what happens to the cell phone microwaves the body absorbs. The energy transfers from the radiation to jostling, jiggling, vibrating and twisting of the molecules. From there, the energy enters to flowing blood, reaches the entire body, and moves to the environment. If the power flow is large, the transfer to the environment will occur primarily by the evaporation of sweat. For the watt or less absorbed from cell phones, the transfer will occur by small changes to the flow of blood to the body’s surface causing slight increases in radiation, conduction, and convection to the environment. There is little temperature increase in a living human being from cell phone microwaves. We know many other processes and effects that produce exactly the same effects at much greater energy and power levels, and all of these are safe and do not cause cancer. Exercise is one such process. Wearing a ski cap is another.

Any researcher who proposes a mechanism by which cell phone radiation might trigger or enhance carcinogenesis is welcome to do so, but must begin with the process described, and also explain why much larger, but otherwise identical processes, do not trigger the proposed mechanism. This thought informs my consideration of the many real and supposed physiological effects of microwave radiation cited by readers.

In the following, I use colloquial language but I could have used the technical terms. Knowledgeable scientists will recognize what these are. I mention specific readers in these notes, but often other readers made similar points.

Richard2010 correctly asserts that it might be possible to modify the complicated and lengthy process by which an initiating incident leads to cancer. He says that microwaves might influence any of the intermediate steps that do not involve breakage of DNA. The only means by which cell phone microwave radiation might influence those steps is through the jiggling, jostling, rocking and rolling that occur when the organism’s thermal control system is functioning. Test tube experiments that do not reproduce the stable temperature conditions in a living organism, however, are not relevant. While some can imagine putative carcinogenic mechanisms from electromagnetic radiation, the only forms of electromagnetic radiation that cause cancer, ultraviolet, X-rays, and gamma rays, operate by breaking chemical bonds in DNA.

Megahurtz, Richard2010, and many other readers assert that microwaves have physiological effects. Some readers cite Russian studies, well known to researchers in this field. Western scientists could not replicate the Russian studies, and do not credit them. Readers point to therapeutic methods. Every therapeutic method that involves microwaves begins with the process I describe. Therapeutic use of microwaves always involves heating tissues.

Monastralblue asserts that microwaves modify chemical bonds or transfer molecules from one quantum state to another nearby state without breaking the bonds. Quantum states of molecules that differ by such a small amount of energy that a microwave photon might cause a transition from one state, the supposedly safe one, to another, the supposedly bad one, will be virtually equally populated in the living organism because of the random shaking, rattling, and rolling of the organism’s molecules. The supposedly bad state will not be empty. If population of the supposed state were bad in some way, carcinogenic or cancer enhancing, then the state would be doing its dirty work at all times.

fscr37 says that Dr. Shermer and I have unstated assumptions and implies that these may be unjustified. The primary scientific assumption that pertains to the question of cell phones and cancer is that the laws of physics apply to biological systems, to organisms, just as they apply to anything else.

The various speculative models, such as the resonance effects to which fscr37 refers, are unphysical and unbiological because they neglect to consider the environment in an organism when they supposedly occur. The energy exchange time, the time it takes for a molecule to transfer energy within its own modes of oscillation or with its neighbors, is about a hundred quadrillionths of a second, 10-13 seconds. This is the result of direct measurements. The oscillation periods of microwave radiation are about a hundred trillionth of a second, 10-10 seconds. That is, molecular jostling will interrupt any buildup of energy by any individual molecule or bond long before the processes frscr37 cites might develop.

Iward notes that the risk that a cell may become cancerous relates to the rate at which it divides. In the brain, for example, neurons divide rarely, if at all, while glial cells divide more often. In adults, brain cancers are gliomas, not neuromas. If there were some effect of microwaves on carcinogenesis related to the division rate of cells, we’d expect that the microwaves might cause skin cancer in phone users’ hands, ears, and scalp. The skin cells divide much more rapidly than any brain cells, and the intensity of the radiation is higher in these skin cells than in any brain cells. Cell phone radiation does not cause skin cancer, and no one fears that it might.

Iward, hereticoftruth, Mark Pine guess that cell phone microwave radiation might have chemical effects other than breaking DNA molecules and refer specifically to denaturing of enzymes. Large, complex biological molecules (and small ones too) take on their shapes through a combination of strong covalent bonds and many weaker chemical bonds, such as hydrogen bonds, van der Waals bonds, and others. Denaturing a molecule refers to the process by which the molecule assumes another form, denaturing. It assumes the denatured form by breaking bonds, mostly weak ones. A cell phone’s microwave radiation absorbed by a living human being cannot denature any biological protein or enzyme unless that radiation can substantially increase the tissue’s temperature in the living organism. High power microwave radiation, much higher than from any cell phone, may damage the cornea in this way. Cooking tissue is bad, but does not cause cancer.

Rivk, tomerg compares microwave cooking with absorbing microwave radiation from a cell phone. Sending microwave power into a roast in a microwave oven causes the temperature of the meat to rise. Sending the same microwave power into a living human being causes the person to sweat with little temperature increase. Dr. Eleanor Adair and others have done this experiment many times. Microwaving a human being causes sweat, not cancer. Can readers guess the difference between a cut of meat and a human being?

Microwaving a person with power levels similar to those of a microwave oven is safe and does not cause cancer. It is not a good idea to microwave a man’s testicles because they prefer temperatures lower than core body temperature. It is a bad idea to microwave your cornea or lens because they have little or no blood supply to provide cooling.

Kiya, jschunke, and pradhangegeorge say that they and other people are hypersensitive to electromagnetic radiation and cite personal experience of these effects from their cell phone use. There is no such thing as electromagnetic sensitivity. It is an imaginary ailment. All double blind tests show that no one can tell if a cell phone or cell phone tower is radiating except through the usual human senses, such as looking at the screen or holding the phone and noting that it is warm. There have been many amusing reports of locals developing vague symptoms when the phone company installs a tower, symptoms that disappear when investigation reveals that the company has not yet installed the amplifiers. Perhaps Kiya would be less prone to headaches if he or she were to choose less annoying people to talk to.

Richard2010 refers to non-thermal effects of microwave radiation. There are none in living organisms, in humans. This fact has not prevented mistaken researchers from doing studies and publishing about non-thermal effects. These researchers mistake the fact that they do not observe a temperature increase with something non-thermal taking place. By their definition, an ice cube melting in a glass of tea or water boiling would be non-thermal effects, but they are thermal effects. Every effect of cell phone microwave radiation must be a thermal effect because the absorbed energy goes into shaking, wiggling, rocking and rolling of the molecules. None of the energy goes anywhere else. If this causes changes to the blood-brain barrier, just to choose one example, then plenty of other things would also cause changes to the blood-brain barrier, such as wearing a ski cap. Wearing a ski cap is safe as long as it doesn’t cover your eyes.

Islesin refers to a comment in Microwave News. This journal has long added to the public’s fears of imagined harm from electromagnetic fields. Scientific American readers may remember the kerfuffle about potential harm from high voltage power lines and household appliances. Microwave News was on the wrong side of that issue too.

On the Internet I am often known as Left Coast Bernard. I say to my neighbor, CaliforniaJoe, that photons are the chunks of energy that carry all forms of electromagnetic radiation, not just visible light.

Agdavis comments on the units in Dr. Shermer’s column, which come from my Skeptic magazine essays. Chemists like to use kJ/mol, kilojoules per mole, which is an energy density, because they like matters relevant to test tube quantities. Using kJ/mol to refer to the energy in a chemical bond is telling us how much energy is in an Avogadro number of bonds, 6 X 1023. An Avogadro number of things is known as a mole, abbreviated mol. A watt-hour is a unit of energy (not a watt per hour); Joules. Physicists would prefer to use a density, just as chemists do. They would refer to Joules/bond or Joules/molecule, while the chemists like Joules per mole, a much larger, test tube sized number. Another reader confuses a mole of cell phones with a mole of photons from a cell phone. Comparing the energy in a mole of chemical bonds with the energy in a mole of microwave photons is correct thinking because it is also comparing the energy in a single bond with the energy in a single photon. The physical effect is, as always, one photon to one bond. Microwave photons do not have sufficient energy to modify any chemical bond, strong or weak.

Monastralblue comments upon safety factors. Here is the way, roughly speaking, that the appropriate organizations establish safety factors for non-ionizing radiation. Since it is a well-established fact that this radiation transfers its energy into tissues as additional shaking, rattling, and rolling, the safety committees find the lowest detectable power level that produces a detectable temperature change, not the lowest level at which some harm occurs. Then they divide this level by 10 or 100. This becomes the official safe level. Exceeding the safe level only means that some temperature increase might be noticed, not that any harm would occur.

62 Responses to “Cell Phones and Cancer”

  1. Max says:

    Interesting, the medical doctors, Dr. Gorski and Dr. Hall, say it’s premature to declare that cell phones can’t possibly cause cancer, but the skeptics who aren’t medical doctors, Michael Shermer, Brian Dunning, and “independent physicist” Dr. Leikind say it’s impossible based on physics. Is Dr. Leikind a Libertarian by any chance?

    • itzac says:

      I think you could safely paraphrase Drs. Gorski and Hall as saying they think it’s almost certainly impossible that cell phones cause cancer. They are qualifying their statements for the sake of intellectual integrity, which is the right thing for skeptics to do. They admit of the possibility that the universe might yet surprise them. But to characterize their statements as in any way supporting the cellphone-cancer link is to misunderstand them.

      Drs. Leikind and Shermer are taking the position that the state of knowledge in the relevant fields is complete enough to say that any as-yet unknown effect could not be large enough to support the idea that cell phones cause cancer. This would be like invoking the theory of relativity to explain the physics of bowling. While relativity, being a fundamental part of the way the universe works, is at play in the motion of a bowling ball, the effect is too negligible to ever impact your score, and to include its effect in your calculations would be a waste of time.

    • Bernard Leikind says:

      I am a Democrat, but in my writing about cell phones and cancer I am wearing my scientist’s lab coat and not my partisan hat. I carefully read Dr. Gorski’s (and Orac’s) essays and Dr. Hall’s essays. Their writing is clear, informed, and effective. See below where I respond to Dr. Gorski’s comments. I carefully read Dr. Novella’s essays too.

  2. Max says:

    Should all research into whether cell phones cause cancer be stopped? I mean, if it’s physically impossible, then this research is as much of a fool’s errand as research into homeopathy or perpetual motion, right?

    • Bernard Leikind says:

      My opinion is that it is a waste of time for any researcher to pursue this matter, and it is a waste of money for any funding source to support it. If someone wants to do it and finds the means to do so, that’s fine. They should talk to physicists while they design their projects and when they consider their results.

  3. “I claim more than that there is no known mechanism. I assert that there is no ‘unknown’ mechanism.” What?

  4. Max says:

    “Every effect of cell phone microwave radiation must be a thermal effect because the absorbed energy goes into shaking, wiggling, rocking and rolling of the molecules.”

    Cell phone microwave radiation induces an electric current in an antenna, which is how cell phones work. The signal strength isn’t measured with a thermometer.
    We know that non-ionizing electromagnetic radiation can induce currents and magnetic fields in the brain, which is how transcranial magnetic stimulation (TMS) and MRI work, so why can’t microwave radiation do this? Dr. Leikind didn’t explain why. Does he even know about TMS? Michael Shermer had an out-of-body experience wearing the “God Helmet”, which generates a much weaker magnetic field than TMS.

    • John says:

      Antenna are made of metal and designed to respond to radio and microwaves. Cells are not. TMS and MRI don’t use microwaves, and the electromagnetic radiation that they do use is of far different signal strength than that produced by cell phones.

    • Ivan says:

      MRI produces basically a pulsating magnetic field.
      Not photons.

      • Ryan says:

        MRI uses a large, static magnetic field and a radiofrequency pulse to generate its signal. So it does use photons, just photons of a different energy than microwaves. The specific absorption rate limit in an MRI is about 4 W/kg, more than double the limit of a cell phone. No serious adverse effects have ever been reported with MRI.

        Microwaves can and do create small electric and magnetic field changes in the brain. However, the net effect of this is simply heating, the “shaking, wiggling, rocking and rolling of the molecules” that we are discussing. Also, TMS works at a much different frequency (roughly 1 to 10 Hz) than MRI (roughly 10 – 100 MHz) thus it is not a fair comparison.

    • Bernard Leikind says:

      Max is correct that microwave radiation induces electric currents in antennas, and we do not measure the currents with a thermometer to detect the signal. If he had a sensitive enough thermometer and planned his measurement carefully, he would be able to detect the temperature increase in the antenna.

      Metals differ from living tissues, and the mechanisms by which they absorb microwaves are different. Freely moving electrons in metals respond to the electromagnetic fields of microwave radiation. A typical electron will oscillate thousands of times between collisions with other electrons, the metal ions, or sound waves in the metal. The collective motion of the many electrons produces the currents and voltages we detect, and the collisions produce resistance and heating.

      Many cell phone users wear earrings. Some earrings are linear antennas and some are loop antennas. These are often closer to the cell phone’s antenna then any of the user’s brain tissue. No one is concerned about the voltages and currents in these pretty antennas.

      I am familiar with TMS and MRI. No one says that microwaves have no effects in living tissues. But I say that it is impossible for those effects to produce cancer.

  5. MadScientist says:

    “… the ongoing controversy over cell phones and cancer.”

    That’s like the ongoing controversy over whether the earth is about 6000 years old or a few billion years old – absolutely all evidence is on the one side and one side alone.

    • Ivan says:

      A lot of people are unsure about electrosmog, compared to very few creationists.
      I know a bunch of very smart people who are unsure about electrosmog, just because they don’t know the physics well enough themselves and can’t assign credibility to what they hear in the media.

  6. I think the difference in approach here relates to field of expertise, and it is not surprising that doctors focus on the clinical evidence while physicists focus on the plausibility of the physics.

    Just looking at the clinical evidence, it is a bit mixed but mostly negative. This is reassuring – there is probably no effect, but if there is an effect is must be very small.

    Looking at the physics, I have no reason to doubt Leikind’s analysis, and it is in line with what I have read from others. I think the main difference between the doctors and the physicist is in characterizing the plausibility. Leikind says “impossible” while the docs say “very low plausibility.” Functionally not much of a difference, but does reflect different biases. In medicine we have learned that biology can be devilishly complex and we are very cautious about declaring something “impossible” – as long as something physical is happening to the body (unlike homeopathy or therapeutic touch which are pure magic). This is why we are uncomfortable breaking out the “impossible” word with cell phones.

    • ^^^^^^^^^^
      This! Remember that a physician may not have a strong background in physics. Just because the word may look alike is no reason to think that there is any understanding between the two fields.

      • David Gorski says:

        Remember also that a physicist may not have a strong background in biology, either.

        Leikind’s Intro to Biology-level understanding of carcinogenesis demonstrated in his SKEPTIC article, in which nothing that does not directly break chemical bonds can cause cancer, shows that very well. Even though I agree that a cell phone-cancer link is highly improbable. I have little faith that Leikind is aware of of understands other mechanisms by which cancer can form, be they known or only suspected but as yet unproven mechanisms. As I’ve said before, Leikind is very likely correct, but unfortunately his main argument is a bad one that relies on a maddeningly simplistic understanding of cancer. In other words, he is supporting an assertion that is almost certainly correct with an argument that is poorly constructed.

        That Leikind still doesn’t “get” the criticism is best illustrated by his use of a massive straw man argument:

        ‘It interests me that so many readers see “microwaves from cell phones cannot cause cancer” and understand us to be saying “there are no physiological effects from microwaves.”’

        Which is not what his critics, including myself, were ever arguing at all! What we argued, quite simply was that Leikind’s argument in SKEPTIC was a bad one. It would be a bad argument even given that he is almost certainly correct about there being no link between cell phone radiation and cancer. Again, quite simply, from a cancer biology standpoint, quite simply, it does not follow from the fact that cell phone radiation can’t break chemical bonds in DNA that it is impossible for such radiation to cause harm or result in cancer. It was only after this was pointed out to Leikind that he seemingly even considered other potential biological mechanisms, plausible or implausible. I encourage Leikind to look up how asbestos causes cancer. Oh, wait. After well over 50 years of trying to figure it out, we really don’t have a very good handle at all on why asbestos causes mesothelioma, but we sure know that it does.

        Even though, as I have pointed out repeatedly, I agree that cell phone radiation almost certainly does not cause cancer, I sense in Leikind a attitude not that far removed from that of the great British physicist Ernest Rutherford, who once said “In science, there is only physics; all the rest is stamp collecting.”

      • Mat says:

        British? Down here we Like to think of him as a Kiwi :-)

      • Bernard Leikind says:

        I agree that Dr. Gorski knows more about cancer and its origins than I do. The subject is more difficult than anything in physics, and Dr. Gorski and his colleagues don’t know everything yet. Not knowing everything, however, is not the same as not knowing something.

        Here are a few correct ideas from various areas that are relevant to this discussion. Biological materials, in common with liquids and solids of similar density and temperature, absorb microwave radiation by rapidly transferring the incoming energy into many kinds of random motions. All bio-chemical processes, both healthy and disordered, involve molecules, their changes, and their interactions. Although every cancer cell has something screwed up in its DNA, the processes that transform normal cells into cancer cells involves many other molecules operating normally or in a disordered manner. Microwave radiation from cell phones, or any other carcinogen, can affect any of these molecules, their forms, their operations, correct or incorrect, or their interactions only if the microwave radiation were to change some kind of bonds in some way. This includes all chemical bonds, covalent, or the various weak bonds, such as hydrogen bonds, Van def Waals bonds, or others. What biological process does Dr. Gorski imagine that does not involve some bonds breaking or adjusting themselves, or some molecule interacting with its neighbors by way of inter-molecular, electromagnetic forces?

        Here are a few more relevant, correct ideas. All biological molecules in living organisms exist and function in a thermal environment characterized by the organism’s body temperature. The molecules incessantly exchange energy with each other and within their internal states in chunks that are a hundred thousand or a million times greater than the energy available from a cell phone microwave photon. For biological molecules to do their jobs, or from them to do bad things as in carcinogenesis by any mechanism, they must function in this maelstrom. In his biochemistry textbook, Dr. James Watson says that one of the hydrogen bonds that hold strands of DNA together breaks about every tenth of a second because of the thermal bonking around. It rapidly reconnects, however, and no harm no foul. Not one microwave photon can ever do anything to any chemical bond that is relevant to biochemistry. The cell phone’s microwave energy enters the thermal jostling around of the molecules, and the body’s thermal control system prevents the temperature from changing by much. Many other processes, such as exercise, produce exactly the same thermal effects but to a much greater degree, and no one believes that they cause cancer. I am sure that Dr. Gorski is correct that no one knows the mechanisms by which asbestos causes cancer, but I am confident that he believes that when the causes are found, they will involve molecules and their bonds.

        Dr. Gorski says that I mis-represent his views when I say that some critics assert that Michael Shermer and I believe that microwaves have no effect. I was not referring to his ideas. A glance at the other comments here will show that several readers wish to inform me that microwaves may heat materials and may produces electrical currents and so on. These readers evidently believe that I don’t know that microwaves have some effects when tissues absorb them. Microwaves have effects, but they do not cause cancer.

      • Max says:

        Dr. Leikind,

        Thanks for replying. So you’re saying that we don’t know what causes cancer, but we do know that microwaves don’t cause cancer. Are you certain that microwaves can’t adversely affect DNA repair mechanisms or gene expression (epigenetics) or whatever else is involved?

        Understanding cancer wouldn’t be necessary if the effect of cell phone radiation is proven to be identical to that of wearing a hat or exercising, although exercise has many non-thermal beneficial effects.

        I know that you believe microwaves only have a thermal effect on living tissues. I don’t know if you’ve considered and ruled out all non-thermal effects in all tissues, or if you haven’t considered them. Which non-ionizing radiation has non-thermal effects?

        I don’t know if asbestos damages DNA, but I recall that saccharin doesn’t. Would you conclude that saccharin can’t cause cancer?

      • Max says:

        Can hot water cause cancer? Is scalding a non-thermal effect? Can microwaves powerful enough to boil water cause cancer?

      • Bernard Leikind says:

        We know a lot about the causes of cancer, but we don’t know everything about them. We know many carcinogens, but we don’t know all of them. Smoking causes lung cancer. Ultraviolet light causes skin cancer, and X-rays and gamma rays cause cancers. These last three are the only known forms of electromagnetic radiation that cause cancer.

        I am certain that microwaves “do not adversely affect DNA repair mechanisms or gene expression (epigentics) or whatever else is involved.”

        The effect of cell phone microwaves on any liquid or solid material (under normal conditions, such as body temperature and atmospheric pressure) is identical to the effects of exercising and wearing a ski cap, earmuffs, or a scarf. All of these processes produce energy within the materials, including living tissues, that is in the form of random jiggling and jostling around. Decades of careful and detailed study by the relevant researchers prove this fact. Exercise, as you say, has other effects, from stronger muscles to sprained ankles, but none of them is cancer.

        As for your questions about thermal effects and my beliefs about them, I am only reporting to you what all physicists know based upon years of detailed research. This is not a matter of belief, but of knowledge, which is true whether you believe it or not. The process by which any tissue absorbs cell phone microwaves are those that operate in any substance in which the molecules are in thermal contact with each other. It doesn’t matter if this material is brain tissue or liver tissue.

        Visible light causes molecules in the rods and cones of our retinas to change from one form to another, isomeric, form. Visible light causes electrons to move around in chlorophyll molecules to power photosynthesis. These are examples of non-ionizing electromagnetic radiation causing non-thermal effects.

        I am not making a general statement about all carcinogens. My argument does not apply, for example, to potential chemical carcinogens, such as saccharin. Molecules contain in their own bonds sufficient energy to modify other molecules’ bonds. We call this modification a chemical reaction. No microwave photon has sufficient energy to modify any chemical bond, strong or weak, that exists in living organisms. As Dr. Gorsky points out, a carcinogen does not have to directly modify or damage DNA to lead to a cancer, so long as it initiates or facilitates processes that lead to DNA damage. Every possible initiating or facilitating process, however, will involve doing things to chemical bonds. As I understand it, just to continue with your example, some researchers say that saccharin causes cancer in male rats by forming crystals that damage bladder cells in the particular chemical conditions of those rats. The rat’s response to this damage begins the process that leads to bladder cancer. Every step in this process involves chemical bonds. Microwaves from cell phones cannot modify any chemical bonds in any molecule in any organism.

      • Bernard Leikind says:


        Scalding tissue with hot water is a thermal effect. Temperature changes in the bodies of living organisms are the result of imbalances between power in and power out. In humans and other warm-blooded animals, the body’s thermal control system, beginning with the flow of blood, works hard to keep internal temperatures at suitable levels. The power absorbed from a cell phone is small compared to typical or common power flows that the body handles easily. Even the power from a microwave oven, about a kilowatt, would be easy for the body to deal with. Researchers beamed microwave power at volunteer subjects at these levels. While sitting motionless in chairs, the subjects began to sweat profusely. When I clomp on a treadmill, I produce about 1200 watts. I sweat a lot. It is possible, of course, to overwhelm the body’s thermal control system, but this would involve much higher power levels. Cooking a living organism, which is a bad thing to do to it, does not cause cancer.

      • NightHiker says:

        And something that has already been said in passing but seems to have gotten lost amidst the comments, is that if any of the effects of microwaves from cell phones caused cancer, they would be very, very small compared with the effects of all the “natural” radiation of the same sort we’re constantly receiving from the environment – there’s no way cell phone microwaves cause cancer and all the other non-ionizing radiation we receive (and generate) in much higher doses all the time don’t. Considering life itself has developed under such environment, natural selection would have assured any organism as sensitive to such forms of radiation as to develop cancer from cell phones was extinct far before it developed cell phones.

    • WScott says:

      Physicists tend to look at things in relatively black-and-white terms of possible vs impossible. Physicians are much more used to “probable vs. improbable.” (No disrespect to either profession intended.)They’re basically saying the same thing, just phrasing it differently due to the slightly different vocabularies of their professions.

    • WScott says:

      Another way of looking at it: The physicist understands exactly how cell phone radiation affects the human body, looks at the known mechanisms for causing cancer, and concludes there’s no possible way for the former to cause the latter.

      The physician, looking at it from the other direction, says we have a pretty decent understanding of the mechanism that causes cancer, and agrees that there’s no way cell phones can affect this mechanism. *But* the physician acknowledges that our understanding of cancer – tho pretty good – is less than 100%, and therefore acknowledges the (highly unlikely) possibility that there could be another mechanism we don’t know about that might theoretically be affected.

      So the physicist starts out on more solid ground (certainty in the physics of cell phone radiation), while the physician starts out on slightly-less solid footing (due simply to the complexity of cancer). So it’s not surprising that the former feels more comfortable making absolute pronouncements.

      • Max says:

        We have a pretty decent understanding of the mechanism that causes cancer? Take a look at acoustic neuroma, which isn’t cancer, but it’ll give you an idea of the limits of our understanding.

        The cause of acoustic neuromas appears to be a malfunctioning gene on chromosome 22. Normally, this gene produces a protein that helps control the growth of Schwann cells covering the nerves. What makes this gene malfunction isn’t clear.
        The only known risk factor for acoustic neuroma is having a parent with the rare genetic disorder neurofibromatosis 2, but this accounts for only a minority of cases.
        Other possible but unconfirmed risk factors for acoustic neuroma include: exposure to loud noise, childhood exposure to low-dose radiation of the head and neck, history of parathyroid adenoma, heavy use of cellular telephones.

      • MadScientist says:

        And don’t forget the statisticians looking at data from various sources around the globe and finding no evidence whatsoever to support the claim that cell phones cause cancer – or as a physician may put it “no increase in cancer rate distinguishable from expected statistical variation”. Ultimately it is not the claim of knowledge or ignorance of a mechanism, but the plain facts that matter. After all, with a fairly small minority excepted, the vast majority of humans over the past 4000 years knew the sky was blue during a clear day even though they had no idea what the mechanism could possibly be. In a similar manner, there is no actual evidence of cell phones causing cancer despite the claims – so it wouldn’t even matter if the cell phone scaremongerers had a thousand sensible mechanisms – the facts say there is no measurable contribution attributable to cell phones.

  7. Chris Howard says:

    I’m writing this on my iPhone, as we “speak.” My index finger, that I type with, left butt cheek, and right ear, are all riddled with cancer… Sorry, drifted into oncoming traffic, for a sec… Anyhow, now I know why. I wonder if there’s a cancer app?

    • Brian says:

      Spinal injury from sitting on an uneven surface (i.e. cell phone in back pocket) is going to have much more impact on your medical bills than the 1 watt microwaves… assuming you don’t hit that oncoming truck!

    • Max says:

      Did you read your iPhone’s safety manual?,8599,2027523,00.html

      “When using iPhone near your body for voice calls or for wireless data transmission over a cellular network, keep iPhone at least 15 mm (5/8 inch) away from the body, and only use carrying cases, belt clips, or holders that do not have metal parts and that maintain at least 15 mm (5/8 inch) separation between iPhone and the body,” the warning reads.

      • NightHiker says:


        Could you tell me on which peer reviewed journal the iPhone manual was published? I must have missed it.

      • Max says:

        The above Time article explains the reason for the warning.

        According to the 2001 FCC guidelines, testing of the device in a “body-worn” configuration should be done with the device in a belt clip or holster. If a belt clip or holster was not supplied with the phone, the FCC told testers to assume a separation distance of between 0.59 inches and 0.98 inches (1.5 cm to 2.5 cm) from the body during a test.
        “Clearly if it’s tested in a holster, it’s only guaranteed to be compliant if it’s used with a holster,” says one current FCC official familiar with these issues, who asked not to be identified by name. “Clearly a lot of people weren’t aware of this, and it probably does need to be addressed.”

      • Badger3k says:

        Time Magazine is peer-reviewed?

      • Max says:

        No Badger3k, Time Magazine is a news magazine that reports things, like the fact that the cell phone warnings stem from FCC guidelines.

        “The FCC guidelines for human exposure to RF electromagnetic fields were derived from the recommendations of two expert organizations, the National Council on Radiation Protection and Measurements (NCRP) and the Institute of Electrical and Electronics Engineers (IEEE). Both the NCRP exposure criteria and the IEEE standard were developed by expert scientists and engineers after extensive reviews of the scientific literature related to RF biological effects. The exposure guidelines are based on thresholds for known adverse effects, and they incorporate prudent margins of safety. In adopting the most recent RF exposure guidelines, the FCC consulted with the EPA, FDA, OSHA and NIOSH, and obtained their support for the guidelines that the FCC is using.”

      • NightHiker says:


        You seem to miss the point about what safety guidelines are supposed to accomplish. They’re supposed to be safe, not accurate. That means that most usually, at least when devised in an appropriate manner, their safety thresholds are many orders of magnitude higher than the actual harmful threshold, if it exists. If those institutions set up their experiments to use given levels of radiation from certain distances and found them safe, then it’s reasonable for the FCC to establish those distances and levels of radiation as a safety threshold. It doesn’t mean that FCC is implying reasonably higher or closer exposures will have any harmful effect, just that they have not been tested.

        Which brings us to the iPhone manual: Apple is not just interested in the safety of their users, but also in legal issues – and in that regard it doesn’t matter really if cell Phone radiation in higher doses causes cancer or not, but that they assure themselves by such disclaimer that anyone who thinks he or she has developed cancer from iPhones has no leg to stand on: if they used them at the correct distance and levels, literature says it’s safe, and if they haven’t, then it’s because they breached the manual safety instructions at their own risk. Therefore, whether they developed cancer from the cell phone or developed it from some other source but think it was the cell phone (a much more likely scenario), Apple will be legally unaccountable.

  8. Max says:

    Dr. Hall said, “Any potential cancer risk pales against the high risk of accidents from using them while driving, and against the convenience and safety effects of having instant communication.”

    So use a wired headset or a speakerphone to reduce the risk of both cancer and accidents. You may even find it more convenient.

    • Amy says:

      Using a wired headset doesn’t take away the distraction. Dr. Novella has spoken on SGU before about humans inability to multitask, just talking on the phone is distracting to safety, even with a headset.

  9. DeLong says:

    Maybe if you ATE the cell phone, there will be medical problems.

    Recently, here in Northern California, there has been a group of people claiming that “smart meters” installed by Pacific Gas & Electric are causing health problems due to the electromagnetic field (EMF) from the meters. These people claim that they are hyper-sensitive to EMF. If that is the case, why do they have electricity in their homes at all? If they are so sensitive, then they should be living in a totally electic free environment! It is entirely possible that many of these same people own and USE cell phones!

    Most, if not all of this, is hogwash. If you believe in this problem, then don’t get modern medical care as there are EMF’s around in every medical office, do not go to work, do not drive a car and do not go outside your cave.

    • Let’s not forget oscillating low frequency of natural EMF. If these people are so sensitive to the alleged effects of EMF then they’re going to have to live in another dimension. Humans have evolved withstanding natural EMF for quite some time. Maybe they didn’t get the memo.

      • Max says:

        What natural low frequency EMF?

      • Bernard Leikind says:

        Perhaps Jose the Paranormal Skeptic is referring to Schumann resonances, which are electromagnetic oscillations in the space between the earth’s surface and the ionosphere. Lightening strikes excite these oscillations. Their frequencies are about 10 or 20 Hertz.

        Max, did you know that infrared radiation fills our bodies? This is a kind of black body radiation that exists because we are mostly empty space and lots of rapidly moving electric charges. These infrared photons, each of which contains much more energy than any microwave photon, are inside us at all times. They are much closer to the energy required to do things to chemical bonds, but they do not cause cancer.

    • Bernard Leikind says:

      I tell my friends not to eat their cell phones and not to text while they drive.

      After learning about the WHO-Interphone study result, that cell phone use slightly reduced the risk of brain cancers, I began encouraging my friends to be careful to alternate which side of their heads they hold their phones to take advantage of this beneficial effect.

      • Max says:

        Deniers of the risk of lung cancer from secondhand smoke gloated over some results showing that passive smokers had a slightly reduced risk of lung cancer.

      • Bernard Leikind says:


        Twenty years ago, there was a fuss about the supposed dangers of electromagnetic fields from high voltage power lines, household appliances, and household wiring. The same fussing that is now occurring with cell phones and microwave radiation erupted then. The same claims that pilot studies, epidemiological studies, animal studies, and so on, showed this or that supposed harm. The same natural fluctuations in the data misinterpreted. In those days, some people shouted about the dangers of electric blankets, hair driers, and clock radios. There were special fears about the dangers to our darling children.

        The situation then with AC power, and now with cell phones, was different from the struggle about smoking and lung cancer. With electromagnetic electro-magnetic fields we understand exactly what happens when any material, including living tissue, absorbs it, and there is no mechanism, plausible or implausible, known or unknown, by which that absorbed radiation might cause any cancer. Also, there is no evidence of any harm, except for texting while driving and so on. In the case of smoking and lung cancer, there were well-known, direct physiological effects from smoking, known from the earliest times. Indeed, those physiological effects are the reason people smoke in the first place. A glance at the Wikipedia accounts of the history of our discovery of the bad health effects of smoking, just to mention one source, will show that many scientists and physicians campaigned against smoking and asserted that smoking caused lung cancer as early as the 1930s, decades before the major epidemiological studies of the 1950s and 60s. Read about Alton Oschner’s campaign against smoking that began in the 1930s. He was a famous surgeon. In this case, there were many plausible mechanisms and strong direct evidence of harmful effects even if no one knew the details of causation.

        There is a long history of false alarms raised because we don’t know about one thing or another. Just to pick one example from many, you might like to read about the history of the introduction of the tomato to Europeans. They were suspicious of the potential harm from this delicious and pretty fruit because the plant is a member of the nightshade family.

  10. feralboy12 says:

    If you get cancer from your iPhone, you’re holding it wrong.

  11. peter says:

    If anyone is worried about cancer from cellphones: just don’t fucking use it, you moron.

  12. Edgaras says:

    Great article, mr. Shermer :)

  13. Denise says:

    New to the Cell Phone debate. Science Daily ran an article a little bit ago, Risk of Brain Tumors From Wireless Phone Use:

    Journal of Computer Assisted Tomography:
    November/December 2010 – Volume 34 – Issue 6 – pp 799-807
    doi: 10.1097/RCT.0b013e3181ed9b54 Special Article
    Rash Bihari Dubey, Madasu Hanmandlu, Suresh Kumar Gupta

    The claim is 10 years of cell phone use doubles the risk of glioma. I have no idea how much credibility the Journal or study deserves. Anyone have any thoughts?

  14. Hi,

    Nice article on cell phones.

  15. XYZ says:

    Disinfo for “liberal” sheeple. Its like saying that sleeping with ur TV on is no danger to ur health. Crappy deceiving idiots!

    • Gark32 says:

      XYZ, you’ll have to forgive me if i (and i assume most others here) dismiss out of hand any remark made by someone that cannot be bothered to spell out words like “Your”, or people that assume radiation is all bad, or that make the outlandish claim that having the Television on while you sleep is somehow worse for you than having it on while you’re awake and can see the drivel that passes for entertainment these days.

  16. Wendy Hughes says:

    In 2006, the Independent Investigations Group (IIG) conducted an investigation into the Aulterra Neutralizer, a product that was a premium on a fundraiser for a local Los Angeles radio station. The claim was that the product would protect users from the cellular phone risks being discussed on this thread. IIG, a grassroots paranormal investigations group comprised of adults who are science professionals and hobbyists, evaluated the claim, proposed hypotheses and conducted tests. The report, on our website, is here:
    The report was written by Steering Committee member Ross Blocher, and includes a link to the details of the test; the investigation was a group effort.
    I have not been afraid of my cellular phones ever since.

  17. Jim says:

    “I assert that there is no ‘unknown’ mechanism.”
    That really does not sound like an assertion that a true skeptic should make.

    • Alchemyguy says:

      Err, no. We have a clear understanding the mechanism by which ice melts or iron has impurities added to form steel; there is no unknown mechanism there. There are times when it is warranted to shut the book.

  18. Skeptic about skeptics says:

    Today the truth is only where the money is. Doctors are sponsored from their toes to scalp. In most cases they talk their payouts from industries they touch with their comments.
    If you want to ensure about something, you have to excel it yourself – if you can.

    Poor ordinary people, wherever they live.

  19. sunny says:

    If cell phones caused brain cancer there would be a sudden and dramatic increase in brain cancer and there is not.

    Some pundits believe there is a sudden and dramatic increase in diabetes so clearly cell phones cause diabetes.

    Some believe that there is a obesity epidemic so just as clearly cell phones cause obesity.

    I just cam back from Hawaii and there were many girls in bikinis talking on cell phones I am happy to report cell phones cause bikinis.

    • Max says:

      Maybe the dramatic increase of brain cancer hasn’t started yet. Cell phone use among children has only become widespread in the last ten years, and it can take 30 or 40 more years for the cancer to show up.

      Do children have a higher risk of developing cancer due to cell phone use than adults?

      There are currently no data on cell phone use and risk of cancer in children. No published studies to date have included children. Cell phone use by children and adolescents is increasing rapidly, and they are likely to accumulate many years of exposure during their lives (1). In addition, children may be at greater risk because their nervous systems are still developing at the time of exposure. A large case-control study of childhood brain cancer in several Northern European countries is in progress. Researchers from the Centre for Research in Environmental Epidemiology in Spain are conducting an international study, Mobi-Kids, to evaluate risk from new communications technologies (including cell phones) and other environmental factors in young people ages 10 to 24.

      • Bernard Leikind says:


        You are correct that effects happen after causes, and that there is often a long delay between the initiating carcinogenic factors and the appearance of cancers. Major international studies have been examining trends in brain cancer incidence. Brain cancer is relatively rare compared to the major killers among cancers, such as lung, breast, and colon cancer. Therefore, the researchers have to monitor large populations, such as all of Scandinavia. So far, the published results of those studies, which compare brain cancer rates going back for a decade or more before the 1990s when usage began to increase rapidly, show no increase in incidence at all. Not even any indication of a beginning of an increase. In fact, these important Danish studies show the same small apparently beneficial effect of cell phone use as other properly designed, large studies.

        It is not correct that there is no data on cell phone use and the risk of developing cancer in children. We know exactly what happens when any materials, including biological materials found in children, absorb microwave radiation. There is no difference between children and adults having to do with the absorption of microwave radiation. The risk that children will develop cancer from using a cell phone is the same as the risk in adults: zero.

        You are correct that epidemiologists have not yet completed their studies. In this case, however, they are the wrong people to ask. Brain cancer is uncommon among adults. It is exceedingly rare among children. In adults the incidence begins to increase in people’s fifties and sixties. Let’s say that there is a 20 year delay between a person’s initial exposure to cell phone microwaves and the development of a brain tumor. A cancer caused by a teenager’s cell phone use won’t show up in the data until the teenagers are in their thirties or forties when brain cancer is rare. There will be hardly any cases, so the epidemiologists will be noticing small changes in small numbers. This is like doing an epidemiological study of astrology beginning by ignoring our knowledge of the size and arrangement of the solar system and stars and the forces among them and all knowledge of biology and evolution and the differing lives of twins.

  20. A skeptic of skeptics says:

    Since we are not omnipotent we do not know everything. I do agree that facts are facts until they’re not – that is, until they are disproved. It used to be a fact our world was flat. It used to be a fact all celestial bodies revolved around earth until Galileo disproved that. Is aspartame really not harmful? Are vaccines really safe to receive? It still is a fact that Mayor Guiliani and Christie Whitman encouraged all of us to venture to NYC right after 9/11 because in their world, it was safe and there was nothing toxic in the air. But I agree that last example is a bad one but I’m leaving it in anyway.

    So, I believe Mr. Leikind believes that cellphones do not cause cancer – they cannot given the facts so well presented by him. However, given enough time facts change.

    — I remain a loyal fan to such a smart gentleman.

  21. Bernard Leikind says:

    Dear skeptic of skeptics,

    Thank you for your friendly comment, which is so different in tone from what many Internetizens prefer.

    I agree with you that we are not omniscient. Even physicists don’t know everything, although we know about what happens to microwaves when materials absorb them.

    I would say that facts do not change. To take your example, the earth has always been, more or less, round. This was the case long before humans existed. Our knowledge changes. The ancients knew that the earth was round, and measured its circumference. They knew that ships disappeared hull-down. They could see its shadow during eclipses. Columbus was not the guy who discovered that the earth was round. Our beliefs and our knowledge changes, as you say. We eventually discover the facts, and then new knowledge doesn’t change what we understand about the facts. Eventually new knowledge only confirms or extends what we understand about the facts. Magellen’s men circumnavigated the globe. We see photographs of the earth from space. Do you believe that the fact of the earth’s roundness might change in the future, after some amazing discovery?