One of questions often posed to the University of Michigan’s Cancer AnswerLine™ nurses is whether there is a connection between cellphone use and cancer — specifically brain tumors.
The basis for the concern is that mobile phones emit radio waves, or radiofrequency energy, a form of non-ionizing electromagnetic radiation, which can be absorbed by the body.
Other devices that emit this low-frequency energy include microwave ovens and radar.
The other form of electromagnetic radiation, called high-frequency or ionizing radiation, is the type used in X-rays.
A link has been established between ionizing radiation and increased cancer risk. But the connection between non-ionizing electromagnetic radiation is less clear.
“I can understand where the confusion and concern comes from,” says neuro-oncologist Aaron Mammoser, M.D. Mammoser treats patients with primary brain tumors and other cancers impacting the central nervous system at the U-M Comprehensive Cancer Center.
“Just hearing the word ‘radiation’ raises a red flag. That’s why it’s so important to reinforce that there is a world of difference between the low-frequency energy from a cellphone and the high-frequency energy from an X-ray,” he says.
Here’s what you need to know.
The findings to date
Recently, the National Cancer Institute published an updated summary on the risk.
“The NCI provided a real service by giving us such a comprehensive and current snapshot of this topic,” Mammoser said of the NCI fact sheet.
“Its overview cites 13 different studies or series of studies, and it reviewed not only the findings, but the methodology behind each.”
“Based on its extensive review of the science to date, the NCI reports that there is currently no consistent evidence that non-ionizing radiation increases cancer risk,” Mammoser says.
Recently, Larry Junck, M.D., another neuro-oncologist at the U-M Comprehensive Cancer Center, commented on the issue in The Wall Street Journal, writing, “Numerous epidemiologic studies considered together do not conclusively show an increase in risk of brain tumors associated with cellphone use.”
“The majority of studies show no association at all. A number of studies do suggest an increase in risk, but some of these studies depend on patients’ recall of their cellphone usage and thus are susceptible to bias.”
Still, additional research on the topic is underway.
“I’m aware of several ongoing studies, including basic animal research into whether increased radiofrequency exposure is linked to increased incidence of cancer, as well as a European population study tracking various health characteristics of cellphone users over time,” Mammoser says.
“That study, known as COSMOS, has already enrolled about 290,000 adult cellphone users. The researchers plan to follow the subjects for 20 to 30 years, so results won’t be known any time soon.”
Children and cellphones
As rumors of the association between cancer and cellphone risk have spread, there’s been particular concern surrounding children, who will live with cellphones for their entire lives, accumulating a lifetime of exposure to radiofrequency energy.
The NCI overview addresses this concern, acknowledging that growing bodies may be more susceptible to cancer risk factors of all kinds.
But as Mammoser notes, though a number of pediatric studies are in progress, so far, research has not established a correlation between children with cancer and the use of cellphones.
The bottom line
“I think it’s reasonable to continue to be curious about the health impact of something that has become such an integral part of our everyday lives,” says Mammoser of the risk and continuing research.
“Considering the huge growth in cellphone use and the frequency and duration of the calls we make, scientists should be just as rigorous in studying this as any other common lifestyle factor.
“To those with lingering concerns, I would echo the FDA’s suggestions to reduce radiofrequency energy exposure.”
“Make an effort to limit the number and length of calls, and since the energy is emitted from the phone’s antenna, take advantage of hands-free calling when possible to limit direct exposure to the head.”