The U.S. Department of Health and Human Services (HHS) announced plans to study the potential impact of cell phone radiation on human health, just a day before Secretary Robert F. Kennedy Jr. publicly suggested that cell phones can cause neurological damage and cancer.
[1]
Kennedy told USA Today in mid-January that “electromagnetic radiation is a major health concern,” adding that he’s “very concerned about it.” Webpages shared on the U.S. Food and Drug Administration’s site that concluded there was no risk to health from cell phone radiation have been quietly removed while the HHS investigates electromagnetic radiation’s potential impact on health.
[1]
This topic has been studied extensively in the past, with scientists and public health agencies around the world concluding that cell phone radiation does not pose a risk to human health. Here’s what the data show, plus what scientists want people to keep in mind.
What Studies Have Found About Cell Phone Radiation and Cancer Risk
Some animal studies have shown a possible link between cell phone radiation and cancer risk, but human studies have not found an association.
One study published in 2018 that is often cited by those concerned about a connection analyzed the impact of whole-body radio frequency radiation on rats at a frequency and modulations used by cell phones. The researchers found “clear evidence” of heart tumors in rats that were exposed to high levels of 2G/3G radiation, emitted by the second generation (2G) and third generation (3G) digital cellular technology in use prior to 2022. (Today’s cell phones rely on 4G and 5G systems.)
[2]
But a significant body of research on humans has found no association. One of the most recent investigations on the topic, published in 2024, was commissioned by the World Health Organization (WHO). It analyzed data from 63 studies on cell phones and cancer from 1994 through 2022 and found no evidence that phones caused brain tumors, even in people with more than 10 years of exposure.
[3]
A nationwide Danish cohort study (following groups sharing common characteristics over time to see how exposures relate to health outcomes) found “no increased risks of tumors” in people who used cell phones. Another study that analyzed data from nearly 777,000 women in the United Kingdom concluded that “cellular telephone use under usual conditions does not increase brain tumor incidence.”
[4]
[5]
While the rat study showed an association between cell phone use and cancer, “subsequent studies with better measurements of exposure showed no such associations, nor did they find that 2G/3G radiation caused DNA damage,” says Tim Rebbeck, PhD, professor of cancer prevention at Dana-Farber Cancer Institute in Boston.
“It’s important to note that the mechanism by which this might occur is unknown. It’s very difficult to imagine how this kind of radiation could cause DNA damage at the level that would be required to induce tumors,” Dr. Rebbeck says.
The data from the one rat study hasn’t been validated in other studies, he points out. “Thus, there is no reason to pursue [more] studies in humans given the vast amount of data that suggests these kinds of radiation exposures will have anything to do with cancer risk,” Rebbeck says.
He also stresses this: “The more recent 4G/5G radiation studies in animals have shown no such associations.”
More Cell Phone Use, More Brain Cancer?
If cell phones cause brain cancer, then the skyrocketing popularity of this technology would suggest that these cancer rates would also increase — but incidence has remained stable.
This is a very important point, according to Mark DeLano, MD, professor and chair of the Michigan State University Department of Radiology in the Colleges of Osteopathic and Human Medicine in East Lansing. “The rates of cell phone use have clearly increased over the time that there was no increase in brain tumors over the same period,” he says. “The conclusion could be that cell phones neither increased or decreased the incidence of brain tumors.”
Research even suggests that brain tumors declined annually by 0.8 percent from 2008 through 2017, a time during which cell phone use exploded.
[6]
“The fact that brain cancer rates have not changed over the period of time that cell phone use became common suggests that there is no strong, epidemiological evidence that might relate increased cell phone use with cancer rates,” Rebbeck says. “Even if there was a long lag between the time that cell phones became commonly used, we should have seen increases in brain cancer rates if the effects were large, given that so many people use cell phones. This has not been the case.”
Cell Phone Radiation Is the Weak ‘Non-Ionizing’ Kind — Why That Matters
Cell phones emit non-ionizing radiation, which Rebbeck describes as “very weak.”
“It doesn’t penetrate into skin or other materials,” he says. “It’s important to recognize that non-ionizing radiation is very different from ionizing radiation, which can cause cancer.”
“Ionizing radiation — for example, the kind of radiation found in the atomic bombs dropped on Hiroshima and Nagasaki or at the Chernobyl disaster — is a very powerful type that leads to numerous biological impacts, including DNA damage among other cancer-causing effects,” Rebbeck says.
Cell phones can heat up, but they don’t reach temperatures that could cause DNA damage (known as a thermic effect), Rebbeck says. Some people concerned about the health effects of cell phones have hypothesized that there may be a nonthermal effect, leading to DNA damage, but Rebbeck says that’s “impossible” due to weak non-ionizing radiation.
“Any symptoms that might have occurred such as inflammation or burns that had any meaningful effect on cancer risk would be noticed by the user and we would be all aware of those dangers,” he says. “They just don’t happen.”
Is New 5G Radiation Riskier Than Older Technology?
Kennedy has suggested that 5G technology may be riskier than older cell phone technology, but research has shown that’s not the case. “This has been studied and there is no difference between 5G and older technology in terms of risk,” Dr. DeLano says.
“None of the non-ionizing radiation exposures are sufficiently strong to cause any kind of DNA damage or other biological effects that might lead to cancer,” Rebbeck says.
So Is It Safe to Sleep With a Cell Phone Near Your Head?
As DeLano points out, this particular risk hasn’t been studied in clinical trials. “From a more practical standpoint, I find it difficult to envision a compelling need to sleep with a phone in close proximity on a prolonged or regular basis,” he says. But, from a cancer risk standpoint, Rebbeck says this should be safe.
