Cell Phones, Radiofrequency Fields, and Cancer

Cell phones give off radiofrequency energy. This is a low-energy kind of radiation, very different from x-rays. In 2011, IARC put it in the weakest "possibly carcinogenic" category. Since then, large studies have not shown a clear rise in brain tumors. Scientists are still watching.

Radiofrequency (RF) fields are a form of non-ionizing radiation. That means the energy is too low to damage DNA directly, the way x-rays can. Cell phones, Wi-Fi, and radio all use RF energy. IARC calls RF fields possibly carcinogenic, or Group 2B. That category reflects uncertainty, not proven risk.

Common ways people come into contact with it:

• Holding a phone against the head during calls.
• Everyday use of phones and wireless devices.
• Heavy, long-term use, which adds more exposure.

IARC looked at a possible link to glioma, a type of brain tumor, in heavy phone users. Large population studies and cancer-trend data have not shown a clear rise. The evidence is still limited.

The International Agency for Research on Cancer (IARC) is the cancer-science agency of the World Health Organization. In 2011 it placed radiofrequency fields in Group 2B, possibly carcinogenic to humans. That is the weakest of the "maybe" categories. The working group based it on limited evidence from human studies, limited evidence from studies in rodents, and inconsistent evidence from studies of how RF energy acts in the body.

Hazard and risk sound alike but mean different things. A carcinogen listing describes hazard. It says the agent can cause cancer under some conditions. It does not describe your own risk. Your risk turns on how much you are exposed to, for how long, and other factors. Two agents in the same group can carry very different real-world risks. The listing answers "can this cause cancer?" It does not answer "how likely is it for me?"

FDA has suggested steps for people who want to cut their RF exposure:

• Cut down the time you spend on your phone.
• Use speaker mode, headphones, or ear buds to put more distance between your head and the phone.
• Avoid calls when the signal is weak, since that makes the phone boost its transmit power.
• Text rather than talk, but do not text while driving.

Are you looking at your overall cancer risk? Small, steady steps add up. To see where cell phone use sits among all the things that affect cancer risk, read our overview of cancer prevention and what raises cancer risk.

Radiofrequency fields are a possible human carcinogen (IARC Group 2B). The most useful thing you can do is learn where exposure comes from. Then take sensible steps to cut it. Do not lose sleep over a single label. Put your energy into the biggest risks you can control.