Study in Rodents Investigates Link Between Cell Phone Radiation and Cancer

The US National Toxicology Program (NTP) has released partial results of a large study it’s conducting in rats and mice to try to determine whether cell phone use causes cancer. Cell phones give off a low-energy type of radiation called radiofrequency (RF) radiation when they’re in use, and that has caused concern over whether or not cell phones can increase cancer risk. Studies done in the past that looked at groups of people have had conflicting results. Some – but not all – found possible links between cell phone use and some types of tumors, especially in the head.

The part of the NTP study that’s been released suggests that male rats exposed to heavy RF radiation to their whole body for long periods of time were more likely than a control group of rats to develop certain types of brain and heart tumors. There was no significant difference in tumor rates among the female rats in the study. The exposure to RF radiation began while the rats were still in the womb, and continued for about 2 years, which is all or most of their life. They were exposed for about 9 hours a day, and received levels of radiation that ranged from the upper limit of what is allowed by law for cell phones, to about 4 times higher than what is allowed.

The findings released in the report focused on 2 types of tumors – gliomas of the brain and schwannomas of the heart. The study found significantly higher (although still low) rates of these tumors in the male rats. The NTP released the information about these 2 tumor types because some studies in people have also found possible links between cell phone use and these types of tumors. The rest of the findings from the study, including the findings about mice, have not yet been analyzed or released, and the study has not yet been published in a peer-reviewed journal.

Otis W. Brawley, MD, American Cancer Society Chief Medical Officer, says these results add to our understanding about how cell phone use may affect human health, but more research needs to be done:

“While this study adds significantly to the evidence that cell phone signals could potentially impact human health, it does not actually tell us how certain scenarios of cell phone use change our long-term risks of getting cancer. For example, the animal studies were performed at very high signal strengths, near but below levels that would cause animal tissue to heat up. Additional research will be needed to translate effects at these high doses to what might be expected at the much lower doses received by typical or even high-end cell phone users. Also, cell phone technology continues to evolve, and with each new generation, transmission strengths have declined and with it radio frequency exposures.”

Are cell phones safe for people?

It’s still not clear whether RF radiation from cell phones cause harmful health effects in people. The results from the study might not translate directly to cell phone use in people because the rats were exposed over their whole bodies, and were exposed for much longer than people typically use their cell phones, and at higher doses of RF radiation. In addition, it’s not clear why tumor rates were higher only in male rats. This does not necessarily mean that any possible effects of cell phone use wouldn’t apply to women or girls. Another unexplained finding of the study is that the rats who received RF radiation actually lived longer than the rats who didn’t.

Still, people who are worried about RF radiation from cell phones can take steps to limit their exposure:

  • Keep the antenna away from your head by using the speaker mode on the phone or a hands-free device such as a corded or cordless earpiece.
  • Text instead of talk. But remember only to text while it’s safe to do so, and never text while driving. According to the Centers for Disease Control and Prevention, any cell phone use can cause distracted driving, which increases the risk of motor vehicle crashes.
  • Limit your (and your children’s) cell phone use. This is one of the most obvious ways to limit your exposure to RF waves from cell phones. You may want to use your cell phone only for shorter conversations, or use it only when a conventional phone is not available. Parents who are concerned about their children’s exposure can limit how much time they spend on the phone.

Additional results from the NTP study are expected to be released in 2017.

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master’s-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.


American Cancer Society news stories are copyrighted material and are not intended to be used as press releases. For reprint requests, please see our Content Usage Policy.