There’s plenty of harm that can come from using our cellphones all the time. Studies have shown that excess cellphone use can impair sleep, delay reaction times and hurt our mental health. But there’s no credible demonstration that cancer is on that list of negative health effects.
Yet in the age of misinformation, there’s no shortage of social media posts and TikTok videos spreading claims that cellphones definitely cause brain tumors either, when in truth, we just can’t say they do. During an interview with Joe Rogan this month, presidential candidate Robert F. Kennedy Jr. claimed that cellphone and WiFi radiation can cause cancer (specifically, fast-growing glioblastomas) by opening up the brain-blood barrier and damaging the mitochondria within the brain.
While it’s true that cellphones emit very low levels of a type of radiation called radiofrequency (RF) energy, studies haven’t detected higher rates of brain and other nervous system cancers over the past 30 years that we’ve been glued to our phones. Some researchers think there “could be some” link between RF exposure and cancer and that we need to pay close attention to further studies, but many studies have so far failed to find a strong relationship between the two.
“There could potentially be a link between prolonged (e.g., decades and decades) use of cellular phones and brain cancer, but we will need many more years of research in order to better clarify this potential association,” Dr. Kelly Johnson-Arbor, a medical toxicologist and the co-medical director of the National Capital Poison Center, told HuffPost.
Cellphones do emit low levels of radiation. Here’s what researchers know about that so far.
Cellphones, along with smart watches and wearable electronic devices, transmit RF energy, which is the same type of radiation expelled by microwaves. This is different from the type of radiation from X-rays, ultraviolet radiation or gamma rays, all of which are known human carcinogens.
But “like microwave radiation, radiofrequency electromagnetic radiation can generate heat, which can cause tissue damage at higher levels,” Johnson-Arbor said. Some researchers speculate that large amounts of RF energy may impact blood flow to the brain, brain metabolism, stress responses and oxygen free radical damage.
But the amount of RF energy our cellphones release is well below the levels associated with tissue damage, according to both Johnson-Arbor and the American Cancer Society. And studies looking into the neurological effects suggest mobile phones don’t appear to impact blood movement in and around the brain. James Giordano, the Pellegrino Center Professor of Neurology and Biochemistry and chief of the neuroethics studies program at Georgetown University, says lower RF ranges — such as what’s released from cellphones — have not been shown to cause cellular DNA changes that could cause cancer.
As noted above, many reports tracking cellphone use over the course of several years have found no convincing evidence there’s a greater risk of tumors among frequent cellphone users. Johnson-Arbor points out it’s been tough to investigate the risk since cancers caused by radiation exposure typically take years, sometimes decades, to develop. Given the uncertainty, the American Cancer Society says the radiation emitted by mobile phones may be carcinogenic, but the evidence just isn’t strong enough to say for sure.
Still, some scientists remain concerned that, even in tiny amounts, RF energy could reach human tissues and cause harm — particularly in the case of cellphones, which are placed against the head, likely multiple times a day. Regardless of the level of RF energy, about 75-80% of it can be absorbed into the skull and underlying tissues (around the inner ear, nerves, and brain), Giordano said. The big unknown is whether this could cause cellular damage over the course of several years.
One meta-analysys, for example, grouped the studies that examined high levels of cellphone use together and concluded they suggest that heavier use (around 17 minutes a day for a 10-year period) increases the risk of brain tumors by up to 60%. Experiments conducted on rats found that radiofrequency electromagnetic radiation exposure — at very high levels, and in some cases, across their entire lifespan — contributed to the development of tumors.
But the rat experiment involved a huge amount of radiation, much more than that level that comes off our phones. Add in the fact that animals respond to and break down toxins differently than we do, and scientists agree: These findings can’t be applied to humans, said Johnson-Arbor.
What we can learn from those reports, according to Giordano, is that overall levels of RF energy and duration of exposure appear to be factors in determining the extent of how much RF energy is absorbed by the body. We just need more research to understand what, exactly, this means for human health.
Should you change your cellphone habits just in case?
There isn’t enough data to suggest you should talk on the phone any less than you currently do. But if you’re concerned about the potential carcinogenic effects, there are some steps you can take.
In general, distance helps reduce radiation exposure, said Giordano. Consider using your speakerphone or low-frequency-emitting earbuds. Hands-free wired headsets (in other words, old-fashioned corded headphones) don’t really release RF energy. Giordano also said “timing is important” — if you don’t have earbuds or don’t want to deal with speakerphone, it may be worth trying to limit your phone calls to a few minutes. Using video chat and texting instead of talking on the phone can help, too, according to the American Cancer Society.
While these tips are believed to reduce the amount of RF energy your brain’s exposed to, Johnson-Arbor noted “there is currently no proof that any of these interventions is associated with a decreased risk of brain cancer development.”
It’s not time to panic, but it may be worth taking a couple precautions. There’s nothing to lose. Even if we eventually learn our phones have nothing to do with the development of brain cancer, we could all benefit from taking a break from them every now and then.