Do 5G, Wi-Fi, and Power Lines Cause Cancer?

This page is for anyone worried that 5G, Wi-Fi, cell towers, or power lines near home could cause cancer. It explains what these signals are and what the large studies found.

Two claims travel together online. The first says 5G is a new and stronger kind of radiation. The second says Wi-Fi routers, cell towers, and the power lines outside a house raise cancer risk.

Both can be checked. The answer has two parts. For wireless signals, very large studies have not found a cancer link. For power lines, one finding about childhood leukemia has never been fully explained. That finding is real, and it is covered below rather than skipped.

The National Cancer Institute splits electromagnetic fields, or EMFs, into two groups.

Ionizing radiation covers x-rays, gamma rays, and cosmic rays. It is high frequency and high energy. It can break chemical bonds and damage DNA directly. That damage can change genes and raise cancer risk.

Non-ionizing radiation covers radio waves, microwaves, visible light, and the fields around power lines. It is low frequency and low energy. NCI states that these fields are not known to damage DNA or cells directly.

Every signal in this argument sits in the second group. NCI gives these ranges:

• In the United States, cell phones operate at about 1.8 to 2.2 GHz, NCI says.
• NCI says 5G phones are expected to use frequencies up to 80 GHz.
• Most Wi-Fi runs at 2.4 to 2.5 GHz. Newer bands run at 5, 5.3, or 5.8 GHz.
• Power lines and house wiring make extremely low frequency fields, at or below 300 Hz. NCI calls these ELF-EMFs.

A bigger gigahertz number sounds worse. It does not move 5G out of the non-ionizing group. NCI defines the whole radiofrequency band as 3 kHz up to 300 GHz. A planned ceiling of 80 GHz sits inside that band. So 5G is the same family of energy as radio and microwave, not a new one.

NCI says the only consistently recognized biological effect of radiofrequency energy from a phone is heating of the area of the body where the phone is held. That heating is not enough to measurably raise core body temperature.

Four large studies dominate this field. None of them found the link the claim describes.

• COSMOS followed 264,574 people in five countries, with a median follow-up of just over seven years. Total call time was not linked to glioma, meningioma, or acoustic neuroma.
• The Danish cohort study matched billing records for more than 358,000 subscribers to the Danish Cancer Registry. It found no link, even at 13 or more years of use.
• The Million Women Study first showed an association with acoustic neuroma. It was not seen with more years of follow-up.
• Interphone, the largest case-control study, ran across 13 countries. Most analyses showed no rise in brain or other central nervous system cancers. One analysis did show a small but statistically real rise in glioma among the heaviest talkers. The researchers judged that result inconclusive.

Two studies looked at young people. CEFALO enrolled 352 children with brain tumors diagnosed between ages 7 and 19, matched to 646 healthy peers. MOBI-Kids enrolled 899 people ages 10 to 24 diagnosed between 2010 and 2015, matched to 1,910 young people having appendicitis surgery. Neither found a link with wireless phone use.

There is a second, simpler check. If phones caused brain cancer, brain cancer would be rising. It is not. NCI reports steady rates for adult glioma in the United States, the Nordic countries, and Australia. Rates for childhood brain tumors in the United States held steady from 1993 to 2013. Rates for acoustic neuroma and meningioma in United States adults have been stable since 2009.

Wi-Fi puts out far less radiofrequency energy than a phone held to the head. NCI says both sit far below the 10 watts per square meter guideline set by the International Commission on Non-Ionizing Radiation Protection.

NCI reports that the United Kingdom's Health Protection Agency studied Wi-Fi in schools. It concluded there was no reason why Wi-Fi should not continue to be used in schools and other places.

This is the part that honest coverage should not drop. Pooled studies of childhood leukemia and magnetic fields keep showing a small signal at the very top of the exposure range:

• A pooled analysis of nine studies found a twofold rise in childhood leukemia at exposures of 0.4 microtesla or higher. Under 1% of children reached that level.
• A meta-analysis of 15 studies found a 1.7-fold rise at 0.3 microtesla or higher. A little over 3% of children reached it.
• A pooled analysis of seven newer studies found a 1.4-fold rise at 0.3 microtesla or higher. Fewer than half of 1% of children reached it.

NCI is direct about what this does and does not mean. So few children were highly exposed that it is hard to say how risk changes with exposure. NCI says the findings could reflect a threshold near 0.3 to 0.4 microtesla or other explanations. Animal studies of ELF fields have not shown a link to cancer.

That mix is why IARC classified ELF magnetic fields as "possibly carcinogenic to humans" in 2002. It judged static electric and magnetic fields and ELF electric fields not classifiable as to their carcinogenicity.

IARC put radiofrequency fields in the same "possibly carcinogenic" group in 2011. The label is easy to misread. It describes how strong the evidence is, not how large a risk is. A verdict of "possibly" means the human evidence is limited and a causal reading cannot be ruled out. It is not a finding of harm. The same logic applies across the common cancer myths people hear most.

FDA says the weight of scientific evidence has not linked cell phone radiofrequency radiation with any health problems. NCI reports that FCC, CDC, and NIEHS have also said the evidence does not establish a link between cell phones and cancer.

None of this is a reason to worry, but the steps are cheap. FDA suggests limiting call time, using speaker mode or a headset, and texting instead of calling. NCI adds that calls in weak-signal areas make a phone boost its transmit power. NCI also says Bluetooth earbuds typically transmit at power levels 10 to 400 times lower than cell phones. Magnetic fields from household appliances fall off sharply about a foot away.

If your goal is a real reduction in cancer risk, a better indoor topic is radon gas seeping in from the soil. The kitchen worry that gets far more attention than it deserves is microwave ovens, which NCI says are shielded so that leakage is barely detectable.

• National Cancer Institute, Electromagnetic Fields and Cancer, reviewed May 30, 2022; accessed August 6, 2026
• National Cancer Institute, Cell Phones and Cancer Risk, reviewed April 4, 2024; accessed August 6, 2026
• U.S. Food and Drug Administration, Do Cell Phones Pose a Health Hazard?, content current as of May 13, 2021; accessed August 6, 2026