Are Cell Phones Dangerous to Your Health? | Chris Kresser
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Are Cell Phones Dangerous to Your Health?


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There’s growing concern over the potential adverse health effects of long-term exposure to electromagnetic radiation from cell phones. Should you be concerned?

are cell phones dangerous
If you use a cell phone, you may not be aware of the potential danger it poses.

If you’re reading this, chances are good you own a cell phone. In fact, it’s probably in your pocket right now, or at least within easy reach. You might even be reading this article on your smart phone.

Twenty years ago, cell phones were still somewhat of a novelty, mildly cumbersome, and were most decidedly “dumb,” with screens just large enough to display a phone number. Now, 90 percent of American adults own a cell phone, and well over half have a smart phone. (1) The question is, what effectif anydoes this have on our health?

In this article, I’ll look at the two most well-researched health conditions associated with cell phone use: male infertility and brain cancer.

Can Cell Phones Cause Infertility?

Several epidemiological studies have found an association between cell phone use and male infertility and decreased sperm quality. For example, a study published in 2008 found that of 361 men attending an infertility clinic, participants who used a cell phone more frequently had lower sperm count, motility, and viability, and had more sperm with abnormal structure. (2) Two other studies also found a higher percentage of abnormal sperm in men who used a cell phone. (3, 4)

Animal experiments have also been conducted to better determine whether a cause-and-effect relationship exists, and what the mechanism might be. Studies where rodents were exposed to cell phone radiation have found decreased sperm motility and abnormal structure, as well as increased DNA damage and oxidative stress. (5) For example, rats exposed to an active cell phone for just one hour per day for four weeks exhibited reduced sperm motility and increased oxidative stress compared to controls who were exposed to a cell phone without batteries for the same period of time. (6)

Is your cell phone habit harming your health? #infertility #cancer

On the other hand, a different experiment found that young rats actually exhibited better sperm motility and structure following exposure to cell phone radiation, which is opposite of what other studies have found. (7) It’s also important to note that animal research doesn’t generalize to humans particularly well in this case. Due to differences in structure of the testes, the doses of radiation used likely have a much larger effect on the animals than it would on humans.

Researchers have also conducted experiments on human semen samples by exposing half of a given sample to cell phone radiation, and keeping the other half as a control. Exposed samples had higher levels of oxidation, as well as decreased sperm motility and viability. (8, 9)

Several thorough reviews and a couple meta-analyses have been conducted over the past decade to summarize the research on cell phones and reproductive health. (10, 11, 12, 13, 14, 15, 16) In general, the authors come to the same conclusion: that a significant amount of evidence does indicate that cell phone radiation could be harmful to male reproductive health, but that the study designs are inconsistent, often not reproducible, and don’t always adequately control for confounding variables. That said, there’s enough concerning preliminary evidence to warrant caution and further investigation.

Do Cell Phones Cause Brain Cancer?

Cancer is another topic that has garnered significant attention from the public with regards to cell phone safety. After all, when most people hear the word “radiation,” they probably think of DNA-zapping, cancer-causing ionizing radiation, like gamma rays or x-rays. So it’s important to keep in mind that microwave radiationthe frequency used by cell phones (and microwave ovens)is non-ionizing, and is actually a lower frequency than UV rays or even visible light.

Because of its low frequency, cell phone radiation does not have the energy necessary to break molecular bonds, so it can’t directly cause cancer by mutating DNA like other types of radiation can.

In-vitro and animal research reflects this—cell phone radiation was not found to cause or promote cancer in isolated human cells or in rodents. (17, 18, 19) But we still have to consider the other effects that cell phone radiation could have on the body, and whether those effects could increase the risk of cancer long-term.

For example, as I mentioned in the previous section, some evidence indicates that cell phone radiation increases oxidative stress in cells, which can lead to DNA damage. Several studies have found increased DNA damage in the brain cells of rats after exposure to cell phones, and since the effect was blocked by antioxidant administration, it’s likely that oxidative stress was the cause. (20) But many animal studies have also found no increase in DNA damage following exposure to cell phone radiation, so experimental evidence remains equivocal. (21)

One of the few human studies involving cell phone exposure found that when two cell phones, one active and one inactive, were placed on either side of a participant’s head for 50 minutes, glucose metabolism increased on the side of the brain exposed to the active phone. (22) This study got a lot of attention, but a subsequent study came up with opposite results, where glucose metabolism decreased on the side of the brain exposed to cell phone radiation. (23) Regardless, the clinical implications of these results (if any) are unknown.

Epidemiological evidence is also inconclusive. The WHO has classified cell phone radiation as “possibly carcinogenic to humans,” primarily based on a couple observational studies that found associations between cell phone use and brain cancer. (24) The first one, the Hardell study conducted in Sweden, was a case-control study that matched each “case” (a person with brain cancer) to a “control” (a person as similar as possible to the case, but without cancer).

They published their results in several papers, reporting an increased risk for brain cancer in people who used cell phones, particularly cancers occurring on the same side of the head that the phone was used on. (25, 26, 27, 28) Risk increased with increasing time spent on the phone, and was highest in people who started using a cell phone before age 20.

The second studythe INTERPHONE studycollected case-control data from 13 different countries, and in contrast to the Hardell study, found no association between cell phone use and brain cancer aside from a small association at the highest level of cell phone use. (29, 30) The authors (as well as two reviews published soon after) concluded that overall, the current data doesn’t support a causal association. (31, 32) But another long-term epidemiological study published later added more evidence supporting a connection, so the case is far from closed. (33)

So, Is My Cell Phone Harming My Health?

The bottom line is that we don’t know. As you’ve seen, there’s quite a bit of research on the safety of cell phones, but the results have been varied and inconclusive. Additionally, the biological mechanisms by which cell phone radiation could cause these adverse health effects are only just beginning to be understood, and until a clear mechanism exists, we can’t draw any conclusions from the epidemiological data we have.

That said, there’s enough concerning preliminary evidence to warrant caution. In a way, we’ve all unwittingly become part of an uncontrolled population-wide experiment on cell phone safety, and the precautionary principle applies: we don’t know that it’s harmful, but it makes sense to take reasonable measures to reduce exposure in case it is.

It’s also important to note that children absorb more cell phone radiation than adults do, because they have thinner skin and bones and a higher water content in their tissues. (34, 35) With that in mind, it’s probably best to limit your child’s exposure to wireless devices like cell phones. (Not to mention the potential adverse effects of too much screen time on children’s attention spans, focus, and cognitive development.)

So instead of holding your iPhone to your ear for that two-hour call, try plugging in ear buds so you can set your phone on the table next to you. If you’re a guy, get in the habit of carrying your phone in a backpack, or putting it in airplane mode while it’s in your pocket. And unless you’re expecting a call, perhaps consider leaving your phone in another room or in your bag. If nothing else, your concentration and connection to the real world will likely benefit from not having your blinking, buzzing cell phone as a constant companion.

Now, I’d like to hear from you. Are you concerned about the long-term effects of cell phone use? Have you taken steps to limit your exposure? Comment below and let me know. 


Join the conversation

  1. Chris,

    In this day and age, I don’t think is is sufficient any longer to simply quote from published studies. We have seen enough corporate shenanigans to know that you should also report who funded the study, and any conflicts admitted by the authors. And this cell phone question involves mega $$billions profits at risk…regards, Dave T (and thank you for all your good work)

    • I recall reading that there was a lot of controversy over the Interphone study and allegations that parts of it (the parts that raised the alarm about cell phone dangers) were redacted prior to publication, over the objection of some of the participating scientiests.

  2. I have worked in Electro-magnetics for many years. I have studied EMF effects and I a very sure that extensive exposure to EMF at many frequencies cause health issues. I am an avid radio operator and have done experiments on myself to feel the effect of long term high level exposure.
    Check out my YouTube video at the link below to get a better understanding of EMF exposure. I concur completely that the effects are mostly due to stress that the EMF causes. We all know that stress is a big killer and connected to cancer over time.

    • Richard, what amazing and convincing demonstrations and, I confess, I didn’t realize about the electric blanket! Of course it is a big antenna and radiates em waves when a current runs through it. If your demo doesn’t convince people I think nothing will.
      I would like to add that when I lived in a very affluent community in California there was a big fight to install a cell tower. The rich (and very informed) people of the town resisted having the tower in their back yard because of the radiation affects on it’s residents. They were happy to continue to use the towers in the poorer adjoining communities!

  3. To think that cell phone radiation does not have a harmful effect on human health is naive. Of course it does. And of course if the radiation hits a human cell in the right place it can trigger cancer. The only question is how much damage does it cause. I have a meter that registers the radiation from cell phones and other sources. Smart phones are very bad, cordless phone bases and wifi routers are worse.

    • I totally agree with you. Thank you! I would question the studies themselves and who actually did them and if they changed or covered up their results, like Monsanto does. If the WHO came out and says what they say, then you know something is up here. There is an epidemic of brain cancers happening right now…what would explain this? Wireless technology is unsafe for all living things. Like unprotected sex, it could be hazardous to your health. Use only with protection, or not at all.

    • I think that we are all unwittingly part of an experiment. Think of numerous medicines and health procedures, operations etc that were once considered safe (smoking was thought of as healthy at one time) and have since proved to be harmful.
      I live 100 yards away from a mobile phone mast (we have a few of them in my area fairly close together). In a cul-de-sac of 15 houses there has been 3 men who have died from a brain tumour in the last 4 years. We are told that this is co-incidence.
      I know that mobile phones are here to stay and are very useful, my gripe with them is that they have increased in complexity – from being used to just phone somebody, to sending pictures and now connecting to the internet with increasing coverage. To provide this internet service and picture messaging there needs to be ever more phone masts because the data is more complex. Hence 2g, then 3g and now 4g. Our phone mast has increased in size and gone from 2 cabinets at the side to 6.
      I wonder what we can do, if anything, to protect ourselves from the masts being built so close to houses. I won’t have Wi-Fi in my house or cordless phones.

      • Jan, I am an actuary (insurance mathematician) specializing in health care. Would it be possible for you to give me the references to this event, and particularly, who conducted the statistical study to declare this “chance?” I would love to get the opportunity to review what was done. While there certainly are cases of perfectly random “clusters” of radiation-related cancers, I would like to provide a second opinion…regards davetrindle at yahoo dot com.

    • It just takes a measurement device screeching at you to understand just what our bodies are being exposed to. The fact the European safety thresholds are so much lower should in itself be cause for alarm. We know someone who has been EMF-damaged and get nosebleeds on exposure. We have been wired for years and, despite increasing inconvenience, will not be otherwise in any near future.

    • For those who comment about using “meters” to measure cellphone radiation… Surely you must have noticed that most cellphones are in battery save mode and not transmitting continuously. During reception, streaming, texting, etc there also is very little output.

    • Um, in the article I did not say that cell phone radiation is harmless. I said there’s enough evidence to suggest that it may be, and the precautionary principle applies. I recommended using a wired headset, not carrying the phone in your pocket or close to your body, and putting it in airplane mode if you have to carry it close to you.

  4. I have bluetooth wireless earphones and I’m wondering they would have a radiation problem.

    • Hello Michael,
      I believe Blue Tube Headsets (not Bluetooth) are the way to go. I think the two features to look for are 1) hollow tubing, and 2) shielding.


      • Blue tube is definitely the way to go, even better then wired headsets. Contrary to some info on the net wired headsets which I have measured are very safe and the wires do not conduct the EMF to your head as some have indicated. Blue tube using non conductive tubes are a real safe bet.

        • Thanks a lot for all your postings Richard plus the videos. What is your opinion on using cellphone via vehicle BlueTooth devices? Just as safe? Will the confined space inside the car amplify the dangers if any? Thanks in advance.

    • Bluetooth are low power devices. They avoid transmissions to save battery power. Some of the smart ones also speak information, but that does not involve transmitted power.

  5. To use the precautionary principle, I have a wired earpiece that I use whenever I’m on the cell phone for more than a minute or two. Also much safer for driving. I never understand how people can spend hours a day with a cell phone right against their head. Not only is it annoying to hold your hand there the whole time, but the radiation source is an inch away from your brain! Maybe it isn’t that bad, but it probably is not healthy!

    • Yeah, the fact that the source of the radiation is right up against your skull is something to consider, much more so than radiation from the cell towers.

      Grounding yourself while you are in the proximity of any electrical device is supposed to offer protection. I ground myself all day at the computer and while i sleep and highly recommend it.

    • re: … wired earpiece …

      Wired headsets are a reasonable alternative to bluetooth, if the phone is not using the wires as part of the antenna system. It’s not immediately clear to me if one can easily determine that.

      You can shut down the possibility by clamping a small toroid around the plug end of the cable.

    • Hi Patricia,
      I have my wifi in the opposite end of my house and upstairs where my desk top computer can just about detect it but where my exposure is minimized. I have a remote switch on the landing of my staircase right in front of my face as I climb the stairs at night and a big sign under it which reads SWITCH IT OFF, before I go to bed. No way should you spend 8 hours a night getting unnecessarily irradiated.

    • Most WIFI modems have a power level adjustment in the setup, many people do not know this. I have mine adjusted all the way down and I still get good device throughout my home.
      I also have a timer on my WIFI modem that shuts it down after bed time and turns back on in the morning. Why would you want to sleep with the modem transmitting all night. the most important time to be free of EMF is while one sleeps. Keep all devices far away from your bed.

    • Perhaps I am being very thick. I have watched this presentation twice and do not understand it! Apparently if you put the shielding cap on, your negative symptoms increase, and I understand that this is counterintuitive. I understand that external radiation affects your immune system but what is the link between shielding the unwanted external radiation and feeling worse? I am not a biologist nor medic. Can anyone out there explain this phenomena in simple terms?

      • The symptoms increase most likely due to immunopathology (like when you get the flu, it is the immune system causing most of the symptoms, not the virus)

        • Thanks Inge, with that in mind I watched it again and I’ve got it. The environmental em waves compromise our immune systems. So if we are fighting a disease and we “turn up” our immunity by shielding ourselves from the radiation our immune system can “fight harder” and cure us, but we feel worse while that (now stronger) fight is going on.
          Hope my interpretation is correct and excuse my simplistic language.

  6. Thanks Chris for your invaluable information always!
    A question on ipads. lying with an ipad resting on the abdomen for long periods of time. Has there been any link to that and swelling of the liver?

  7. Of course cell phones are dangerous: how many people have gotten injured tripping over something while watching their cell phone screen rather than the real world? How many car accidents have happened due to people being distracted by their cell phone while driving?

    The risk of something like that happening is immensely bigger than any radiation risk. Cell phones are wonderful, ingenious devices, but you do have to be careful with them.

    On the other hand, due to the fact that cell phones are everywhere nowadays, an ambulance can be quickly called in almost any situation and a robber can be identified with the video that a witness can instantly make.

    Anyway, I am not saying that radiation might not be harmful, but going crazy with fear over this and then cheerfully stepping into your car (driving a car even with a distracting iPhone increases the risk of doing harm or getting harmed significantly)… Perhaps that decreasing your car mileage a few percent by smartly combining errands does a whole lot more for your health than keeping the cell phone at a few inches more distance.

  8. I wish someone would prove that shouting into one’s mobile phone makes any adverse effect much worse!

  9. If it is that dangerous the government would not allow/discourage that to be investigated as our whole economy is now based on that technology. It is too controversial. The economy comes first and second and last.
    Keep up the good work and in letting us know how to protect ourselves better, we are listening.

    • Right, and bear in mind that the FCC is dominated by telecommunications industry hacks.

  10. “The bottom line is that we don’t know. ”

    Considering how Jack K tore you a new back end regarding microwaves, is anyone taking you seriously?

      • Marie, now let me guess..
        You’re one of those disgruntled gals who spat the paleo-pop and when Jack brought the news “It’s not about the food!”.
        Fair enough not everyone likes Jack Kruse, but at least his messages remind us we evolved on earth under a specific set of environmental conditions and we can reconnect with those if we choose.
        Unlike some he hasn’t decided to launch “I can’t believe it’s not a hot fudge sundae!” Paleo bars or “EmpowerEmpire” supplements to ease you more deeply into the LIE you’ve got to be a consumer to be well.
        …Now THAT would be dodgy.

  11. For my family, some cell phone use is necessary. We live too far into the forest to run phone lines (or power, for that matter). To limit the potential harm, we do not ever put the phone near our head (or really any other part of our body for prolonged periods), nor do we use a Bluetooth device (this drops the wattage to about 1/3, in my understanding, but still exposes the body to radiation). We utilize an air tube headset (like a stethoscope) to bring the sound from the phone to our ears. There are a few models, though most are cheaply made and fail after a short time. The only model we have had luck with any longevity is the Tubez version. We also keep the phones on airplane mode when not in use (to limit exposure). While cell phones might be great for staying “connected”, they are a new technology that is yet unproven in its harmlessness. I choose not to enroll my family into another modern experiment placing cell phones against our head and waiting to see what the long term results are. Thanks for the article Chris.

    • re: … nor do we use a Bluetooth device (this drops the wattage to about 1/3, in my understanding, but still exposes the body to radiation).

      BT is more like 1/1000th the maximum power permitted for cell phones, but I’d estimate that the ratio in practice is more like 1/100th. The further away from the nearest cell tower you are (as in your case), the harder the phone has to work. The simple precaution of using almost any kind of headset is prudent, and for more reasons than RF. The biggest increase in fatalities due to cell phones, and one about which there is no doubt, is automobile crashes (and headset use merely lowers that risk a bit).

      re: While cell phones might be great for staying “connected”, they are a new technology that is yet unproven in its harmlessness.

      They’ve been around for 30 years now. If there was an inherent cause-effect resulting in cancer, I suspect we’d have seen a bigger rise in the ailment. Confounding matters, of course, the RF power, carrier frequencies and modulations have been changing the whole time – and three parties theoretically assessing mobile RF risk (phone makers, carriers and government) cannot be trusted to run meaningful studies, or tell the truth about outcomes in any case. And almost everyone is digging in the wrong place due to the failed somatic theory of cancer.

      There is also the likely role of diet in reducing all-cause cancer risk, perhaps substantially, but that’s a topic drift for another time.

      • Dear Bob, thank you for your comments. You and I do differ very much on what we consider to be enough time to have elapsed to diagnose the safety of a new device (or new food, new medicine, etc.). Thirty years is almost meaningless to me–I want generations of exposure to understand the true effects of a new technology. If we only used thirty years with many foods that are now staples in the American diet, we wouldn’t have a good understanding of how they effect epigenetic expression (and the health of later generations). I regard this issue of what modern people consider to be a long period of time as a fundamental problem is how we approach the safety of many common things (food, devices) in our society. Thank you, by the way, for the information on Bluetooth, though you are presenting very different numbers than those supplied by the AT&T staff member I spoke to about this topic. Again, thank you for the conversation and best wishes.

  12. I had seen on the local news a experiment done at a primary school were the teacher and kids planted seeds in a container next to a wifi router and same seeds in a container in a room without wifi both in good soil and watered. The seeds in the the room without a router sprouted fine though the seeds next to the wifi router never sprouted.

    • Excellent experiment, simple, basic, gets to the point, radiation affects living cells. That teacher probably saved her pupil’s lives, or at least their future health, how could anyone forget such an experiment.

  13. Ref the bluetooth and use of earbuds… sadly not, a EMF meter shows the levels are the same via these devices, speaker phone mode is better or hollow tube buds with no internal wires. . .

    I believe the French government has also banned use of mobile phones since 2009 in primary schools. And many progressive European countries have banned WIFI routers in schools and some government buildings, library etc. The above BIOINITIATIVE report 2012 also highlights the damage Electro smog can do to the Blood Brain Cell barrier and the blood-placenta barrier (that protects the developing fetus) and in view of last nights Webinar on Gut health and blood brain barrier discussions, EMF exposure is very relevant. I believe there is research also on women increased risk of developing Breast cancer when carrying their phones in their bras. I’m no expert but the standards for assessing radiation levels are archaic, and they are adult dose…. our children are not little adults, (as the WHO have pointed out in 2005) and as you point out in your article. Again I’m no expert, but the WHO lists 50hz magnetic field, which relates to a host of electro smog, including radio frequencies (RF), Electromagnetic rays (EMF’s) emitted by WIFI and other electronic devices such as mobile phones, DECT (Handsfree) phones, computers, Smart meters, Meter & fuse boxes, microwaves, fridges, fluorescent bulbs (CFL), inverters, ceiling fans, halogen down lights etc. so it is not just cell phone radiation that is a concern. However, DECT phone have been around a lot longer than cell phones and it has been proven that the use of a DECT (Handsfree) phone, for half hr everyday on the same side of the head, will increase your risk of a brain tumour by 470%!!! (BioInitative report, 2007). WIFI, DECT and mobile phones operate on the same frequency. And children have a five-fold increase of brain tumours if they use mobile phone (Swedish Professor Hardell in 2008). Again I’m no expert, but in 2011 The Council of Europe suggested, waiting for high levels of scientific proof before taking action on electromagnetic fields can lead to very high health and economic costs, as in cases of asbestos, leaded petrol and tobacco. . . . .

  14. re: … so it can’t directly cause cancer by mutating DNA like other types of radiation can.

    This presupposes that the somatic (gene) theory of cancer is correct, which looks increasingly unlikely.

    Under the metabolic theory (Warburg/Seyfried), all that’s needed is mitochondrial damage, which can happen at less than ionizing levels of RF.

    My understanding is that there is a correlation between phone side of head, and on which side the brain cancer is found.

    This risk, if real, can be dramatically reduced by using a bluetooth headset, which emits two orders of magnitude less RF power.

    Separately, the blue-light-at-night hazard also increases the risk of cancer. Burying your face in a cell phone (or tab) at night, without f.lux or wearing blu-blockers, could be a problem.

  15. One of Andrew Marino’s areas of research is, interestingly, why are there discrepancies in the research done on EMFs?

    He seems to have come to the conclusion that we need more non-linear (bio)physics based models utilized in studies, as opposed to linear models which largely hide results. This doesn’t even begin to get into the work of Mae Wan Ho, PhD, GIlbert Ling, PhD, etc. and cell water, cellular cytoskeletal make up, tubulin, etc. Things that are much more difficult to measure than simply glucose in blood, or something such as that. “The purpose of this presentation is to describe the inherent limitations of the present scientific paradigm, and to indicate how some important scientific problems might be satisfactorily resolved by looking at the world in a nonlinear way. In my view, one such problem involves an understanding of the mechanistic basis by which environmental electromagnetic fields can give rise to health hazards. Resolution of the EMF hazards issue was used as a particular example of the power of biological nonlinearity to explain the meaning of bona fide data ”

  16. Chris, you should look into the work of:

    Andrew Marino, PhD – Biophysicist; has researched EMFs, their impact on the brain, how we perceive them, etc, for decades

    Robert O. Becker, MD – Nobel Laureate, surgeon, etc. who studied the harmful effects of EMFs, and how some frequencies of electromagnetic radiation can also be harnessed for tissue regeneration

    George Washington Crille, MD – a surgeon in the 1900’s who researched radiowaves and various forms of EMF and considered electromagnetism as the basis for life

  17. Chris how about wifi routers we now all have in our apartments? It looks like a much bigger concern to me. Thanks.