Is cell phone radiation harmful? What the FDA, NCI and WHO say

By the EMFCALM team · Updated November 9, 2026

US and international health agencies have not found that the radio waves from cell phones cause cancer or any other disease at the levels phones give off. The FDA and the National Cancer Institute (NCI) both say so, and a 2024 review of 63 research papers, commissioned by the World Health Organization, found no rise in brain tumor risk among phone users. Both also say the studies so far had limited power to catch a very small risk in a small group of people.

What kind of radiation comes from a phone?

Phones reach the network with radio waves. According to NCI, 2G, 3G and 4G phones use 0.7 to 2.7 GHz, and 5G phones are expected to go up to 80 GHz. All of it is nonionizing radiation, with energy that "is too low to damage DNA." X-rays and radon are ionizing, the kind that can.

Your body does absorb some of a phone's energy. NCI says the only consistently recognized effect is mild heating where you hold the phone, not enough to measurably raise your core temperature, and that no other dangerous effect has been clearly established. WHO also names heating as the main way RF fields act on the body.

What does the FDA say?

The FDA shares oversight of cell phones with the Federal Communications Commission, which sets the emission limits. The FDA's cell phone page (content current as of May 2021) says "the weight of scientific evidence has not linked cell phone radio frequency radiation with any health problems," and that the evidence doesn't show a danger to children and teenagers either.

The fuller statement is a February 2020 technical report, the FDA's review of published literature on radiofrequency radiation and cancer from 2008 to 2018. Of about 125 animal studies, none adequately showed harm from RF at the levels phone users get, the report says. Of about 70 human studies, some suggested a link between heavy use and certain tumors, but no clear and consistent pattern emerged. The FDA concluded there are "no quantifiable adverse health effects in humans caused by exposures at or under the current cell phone exposure limits."

The part we found most useful is where the report admits what it couldn't settle. People in these studies reported their own phone use, so the actual exposure is "an estimate at best," and very few of the studies looked at Americans. The studies also lacked the power to detect a small effect limited to one subgroup. If any risk exists, the FDA says, it is extremely low compared with the natural rate of the disease.

The National Toxicology Program's rodent study found a small number of heart tumors in male rats exposed over the whole body at 3 to 9 W/kg. After its draft results in 2018, the FDA said the phone limits were still acceptable for protecting public health (our NTP guide has the details).

What did the big human studies find?

NCI's cell phone fact sheet, last reviewed April 4, 2024, says the evidence to date suggests phone use does not cause brain or other cancers. It calls the findings of four large studies mixed, but says that overall they show no association, and it describes two large studies of young people.

Sources: NCI fact sheet and the study abstracts on PubMed, read November 9, 2026. A ratio near 1.0 means no difference in risk.

The Interphone heavy-user number deserves a careful read, since it came from the group where the authors flagged implausible answers. As the fact sheet explains, people with a brain tumor may remember their phone habits differently from healthy people, and they are more likely to agree to join a study. Cohort studies may only know who held a subscription, not who used the phone.

Has brain cancer become more common since phones spread?

No, according to NCI. The studies it cites found stable rates of adult glioma in the US, the Nordic countries and Australia over several decades, and stable rates of childhood brain tumors in the US from 1993 to 2013. The FDA report says brain cancer incidence in SEER, NCI's cancer registry program, has not risen over the 20 years before the report, while phones became nearly ubiquitous.

In the SEER 8 registries the highest rate since 1975 came in 1990, at 7.17 new cases per 100,000 people, and the lowest in 2023, the latest year, at 5.66. SEER's trend model has new-case rates falling 1.4% a year on average from 2014 to 2023.

Trend data follows whole populations instead of comparing users with non-users, so its ability to see a small difference among heavy users is limited. It still works as a cross-check: simulations described in the fact sheet show many of the raised risks reported in case-control studies don't fit the incidence data.

What does the WHO say?

WHO's Q&A on 5G and health, dated February 27, 2020, says that "to date, and after much research performed, no adverse health effect has been causally linked with exposure to wireless technologies." The same WHO page says WHO backs more research on long-term effects, and notes that only a few studies had been done at 5G frequencies (see our 5G and health guide).

The newest big review was commissioned and partly funded by WHO and published in Environment International in August 2024. Its first author is Ken Karipidis of ARPANSA, Australia's radiation protection agency, and it covers 63 papers from 1994 to 2022.

All six confidence intervals include 1.0, so none of the estimates shows a clear difference in risk. Risk didn't climb with years since first use, total call time or number of calls. For people who had used a phone for 10 years or more, in the studies rated at low risk of bias, the glioma estimate was 0.95. The authors rated their conclusion for mobile phones as moderate certainty: phone use likely does not raise the risk of these tumors in adults, or of brain tumors in young people. For cordless home phones they rated the certainty as low.

The review found no eligible studies on cell towers or broadcast antennas and tumors in adults. It has drawn published criticism, and the authors replied in the same journal in January 2025.

You may have read that IARC, WHO's cancer research agency, classified RF fields as "possibly carcinogenic to humans" (Group 2B) in May 2011, based on an increased risk of glioma linked with wireless phone use. That label rested on limited evidence from human and rodent studies, as NCI points out; our guide to the 2B label explains what the group means.

How the FCC limit works

Since 1996 the FCC has required every wireless device sold in the US to meet its RF exposure guidelines. For phones the measure is SAR, the rate at which the body absorbs RF energy, and the FCC limit is 1.6 watts per kilogram averaged over one gram of tissue. Phones are tested at their highest possible power, and the FCC says the limits include "a considerable safety margin."

The FCC bases its rules on IEEE and NCRP standards. Its RF safety FAQ says those guidelines and ICNIRP's share one threshold where harmful biological effects may occur: a whole-body SAR of 4 W/kg. The federal rule caps whole-body exposure for the public at 0.08 W/kg, a fiftieth of that, and phones must also stay under the separate 1.6 W/kg limit for any gram of tissue. Europe and most other countries use ICNIRP's 2 W/kg over 10 grams, which the FCC calls somewhat less restrictive.

The FCC consumer page, last reviewed November 4, 2020, says no scientific evidence establishes a causal link between wireless devices and cancer or other illnesses, and that there is no basis for a different threshold. It also says more and longer-term studies should look for a better basis for the standards.

Where the agencies agree, and what they leave open

None of these agencies says phone RF at or under the limits has been shown to cause cancer or other disease. They differ in the details: the 2011 IARC label sits next to newer reviews that found no rise in risk, and the US averages SAR over 1 gram of tissue while most countries use 10. The open questions are about small risks. The FDA says the studies lacked the power to spot a small risk in a subgroup, and the MOBI-Kids authors couldn't rule out a small increase in young people.

If you'd like lower exposure anyway, the FDA's steps, as NCI lists them, are free. Spend less time on calls. Use speaker mode or earbuds. Avoid calling on a weak signal, which makes the phone boost its power, and text instead of talking, though never while driving. Our guide to reducing EMF from your phone walks through each step, and the AirPods guide covers Bluetooth earbuds, which typically transmit at 10 to 400 times lower power than phones.

The driving part matters most. NCI names distracted driving and vehicle accidents as the most consistent health risk linked to cell phone use.

This guide summarizes what public agencies and published studies say. It is not medical advice.

General information about radio-frequency exposure from everyday devices. Not medical advice.