Most Americans (96%) have a cell phone these days and we check it 52 times a day on average, with 75% of us admitting to rarely or seldom turning it off. That all adds up to a lot of time spent with our phones. So a recent animal study from the National Toxicology Program (NTP) of the U.S. Department of Health and Human Services showing that cell phone radiation caused significant increases in DNA damage in lab mice and rats is raising questions once again about what cell phone radiation might be doing to humans.

DNA damage in mice

Cell phones emit radiofrequency (RF) waves, and the new study found that two common RF waves emitted by cell phones caused DNA damage in mice and rats that were exposed intermittently for a total of slightly more than nine hours per day for 14 to 19 weeks. The frequencies were the same used in older 2G and 3G technology than today’s 4G and emerging 5G technologies and the level of exposure was similar to or just slightly higher than potential exposures a human would get from holding a cell phone close to their head, the study authors point out. In the past, it was thought cell phone-generated RF was safe if it did not heat the body’s tissues, but in the new study, cell phone radiation was linked to DNA damage even at levels that did not involve any heating. The findings are published in the Journal of Environmental and Molecular Mutagenesis.

A growing body of evidence?

This is not the first study to find such a link. Some studies in humans have shown evidence of a statistical association between cell phone use and brain tumors, but most studies have not. For these reasons, the American Cancer Society issued a statement in 2018 noting that the findings from the NTP at that point were still inconclusive. Some experts, however, feel that this study tips the scales. “These findings confirm many other studies and show clear evidence of DNA damage. With each review, the findings become stronger,” warns Devra Lee Davis, PhD, MPH, founder and president of Environmental Health Trust in Teton Village, Wyoming.

How might cell phones cause DNA damage?

The mechanism by which cell phone radiation causes DNA damage is not fully known, says Ron Melnick, PhD, lead designer of the study and a retired senior toxicologist at the National Institute of Environmental Health Sciences. “There are numerous studies showing evidence of oxidative stress in animals and cell cultures exposed to this type of radiation, and it is known that oxidative stress can lead to mutations, chromosomal translocations, and genetic instability,” he tells Reader’s Digest. Oxidative stress occurs when there is an excess of free radicals, which are destructive fragments of oxygen that have been linked to cancer and other diseases.

Are 4G or 5G networks any safer?

While 4G and 5G networks use less power than 2G and 3G networks, it doesn’t mean they are safer, Davis says. Melnick agrees: Much higher frequency 5G radiation does not penetrate into internal organs as does current cell phone radiation, he says. “However, there are no adequate health effects studies on 5G, so it is difficult to opine with any credibility on the safety of 5G radiation.” Specifically, there is no information on whether exposure to 5G will cause eye injury or increase the susceptibility of skin cancers. The NTP is evaluating the literature on 5G and will initiate additional short-term studies to better understand any damage.

Where do the public health agencies stand?

The World Health Organization (WHO) lists cell phones as a Class 2 B Carcinogen. This means that they are “possibly carcinogenic to humans.” The U.S. Environmental Protection Agency (EPA) and the National Toxicology Program (NTP), have not formally classified cell phones in regard to cancer-causing potential.

Not so fast…

Not everyone is so sure that cell phones are hazardous to our DNA.

“There is no biological plausibility,” says Norman J. Kleiman, PhD, assistant professor of environmental health sciences at the Columbia University Medical Center and the director, MS degree program in Radiological Sciences & Toxicology in New York City. “If radiation is causing DNA damage, we need a mechanism by which this is occurring, and we don’t have one.” The new study is “well-done and had a reasonable number of animals, but we are still scratching our heads as to why this would be happening. We don’t know.”

If cell phone radiation were a true threat, it would be seen across studies and animal types and the effect would be much more significant, Kleiman says. “I’m skeptical of the findings but cannot 100 percent exclude the possibility that there is some effect,” he says. “We are waiting for the definitive study.”

Minimize exposure from cell phone radiation

The real question is are you willing to wait it out and take the risk? Davis asks. “We should be very concerned and it is time for the industry to take more steps to design safer phones,” Davis says. For example, case design changes may reduce exposure to RF pulse and power. Still, there are some practical steps you can take today to protect yourself from any possible effects of radiation, including:

• Mind your apps. The more apps that are open or running, the more RF radiation your phone is emitting. Turn off automatic updates and push notifications, delete those apps you don’t use and close apps when you are not using them, she warns. Bonus: These steps should also improve the battery life of your phone.
• Opt for airplane mode. Keep your phone on airplane mode or turned off when it is not in use, Davis says. Airplane mode stops the microwave radiation emissions, which could interfere with the operation of an airplane.
• Watch how you carry your phone. As a general rule, carry your phone in your briefcase or pocketbook and place devices on desks, not laps, Davis says. And never put it in or near your bra, she warns. Here’s why you should never bring your cell phone to the bathroom.
• Avoid close contact with your cell phone. Use speakers, headsets, or text (but not while driving, obviously), Melnick says.
• Don’t use your cell phone when the signal is weak. When your signal is low, your phone works even harder and emits greater intensity of radiation to maintain communication with the cell tower, Melnick says.
• Restrict the use of cell phones by children. Kids are more susceptible to tissue-damaging agents because of their developing nervous system, Melnick says. Specifically, the American Academy of Pediatrics cautions against screen time for children younger than 18 months. Try these strategies to get your kids off their phones without resorting to bribery.