Perhaps the biggest difference between life now and life a generation ago is that we are all constantly connected to each other and to the internet. The devices many of us use more than any other—both to talk on the phone and connect to the internet—are cell phones.
So it may seem scary that the California Department of Public Health has issued guidelines to help people “decrease their exposure to the radio frequency energy emitted from cell phones.” The department said the information was intended to help people who are concerned about health risks including brain tumors, lowered sperm counts, and effects on learning, memory, and sleep.
But California’s new guidelines—and some of the news coverage they have inspired—can make it seem like using a cell phone carries far more risk than scientific evidence suggests.
Although some researchers are worried about the long-term effects of cell-phone use, so far there’s not actually any evidence that the radiation emitted by smartphones causes harm.
The CDC’s position is that there are no scientific findings that provide a definitive answer to the question of whether cell phone radiation causes cancer. Most large studies documenting cancer rates haven’t found significant evidence that cell phone use raises cancer rates or causes other negative health effects.
There are some good reasons to limit cell phone use, however.
California’s department of public health suggested that people who want to reduce their risk of radiation exposure could take the following steps:
- Keep the phone away from the body
- Reduce cell phone use when the signal is weak (since searching for a signal could use more energy)
- Reduce the use of cell phones to stream audio or video, or to download or upload large files
- Keep the phone away from the bed at night
- Remove headsets when not on a call
- Avoiding products that claim to block radio frequency energy, since such items may actually increase your exposure
The main concern people have about cell phones is that they emit radio-frequency (RF) energy, a type of radiation. Researchers have long wondered whether that could pose a threat to human health. But RF energy doesn’t cause the DNA damage that radiation from the sun or from X-rays does, according to the National Cancer Institute. (DNA damage is the thing that leads to cancer.)
The International Agency for Research on Cancer (IARC) classifies RF energy as “possibly carcinogenic,” but almost everything is “possibly carcinogenic,” including coffee and pickled vegetables. It’s hard to definitively say that any substance doesn’t cause cancer, even when we have evidence that substances like coffee are linked with lower cancer rates. (Out of 968 substances IARC has evaluated, the only one they’ve concluded is “probably not carcinogenic” is a chemical used in yoga pants and toothbrush bristles.)
Given the widespread adoption of cell phone use, scientists would expect cancer rates to have spiked if usage was really risky. But that hasn’t happened.