Myth vs. Fact: Smartphone Use and Brain Tumor Risk

The debate over smartphones and whether the radio frequency waves they emit can pose a health hazard to users has heated up in recent days.

The largest smartphone makers, Apple and Samsung, have been hit with a class-action lawsuit over claims that their phones expose users to radiofrequency emissions beyond U.S. government-mandated limits.

Smartphones give off a form of energy known as radiofrequency waves. At very high levels, this type of emission can heat up body tissue. But the levels of energy given off by mobile phones are much lower, and are not enough to raise temperatures in the body, according to the American Cancer Society.

No major public health organization has been able to link cell phone use with cancer or other serious ailments. But myths persist about the regular use of mobile phones and the potential of increased risk of developing a brain tumor.

The U.S. Federal Communications Commission, which oversees the mobile phone industry, states on its website that if a cellphone has been approved for sale, the device “will never exceed” the maximum allowable exposure limit. However, a report from the Chicago Tribune this month found that popular smartphones exceeded the maximum limit for exposure to radio frequency emissions set by the FCC at various distances. In response, the FCC says it will do its own testing of smartphones.

“Overall, if you look at the data that has been collected, there is no increased risk of brain tumors associated with cellphone use,” says Minesh Mehta, M.D., deputy director and chief of radiation oncology at Miami Cancer Institute. “There are over a dozen studies in the literature that show no indication of increased risk of brain tumors with mobile phone use.”

The Cellphone-Brain Cancer Myth
How did the supposed link between cellphone use and brain tumors get started? Initial clinical studies that looked at the health impact of cellphone use carried a bias — they looked at patients who were already diagnosed with brain tumors, explains Dr. Mehta. Many study participants would typically say they placed their cellphone on the side of their head where the tumor was located.

“These studies were done by looking at people that had tumors, and then subsequently trying to determine whether there was an association with the use of cellphones,” said Dr. Mehta. “That caused this fiction that there is an association between cell phone use and tumors.”

Subsequently, much larger epidemiological studies have been done “basically looking at much larger populations,” he said. Epidemiology is the study of diseases in populations of humans, specifically seeking out answers as to the cause and other characteristics of cancers or other diseases.

Longer-Term Effects?
But Dr. Mehta and health organizations caution that more studies are needed to determine longer-term effects of mobile phone use — mostly because the technology is evolving so quickly and the persistent use of mobile phones have been around for only about two decades.

“Large studies that have followed patients for five to ten years have not shown any categorical evidence of an increase in risk of developing brain tumors with cellphone usage,” says Dr. Mehta. “But what about 20 years of use? What about 30 years of use? Obviously, we just don’t have the data for that right now, and since we don’t have the data that leaves the myth open to interpretation.”

According to the National Cancer Institute: “Studies, thus far, have not shown a consistent link between cell phone use and cancers of the brain, nerves, or other tissues of the head or neck. More research is needed because cell phone technology and how people use cell phones have been changing rapidly.”

Tags: Brain Tumor Program, Miami Cancer Institute