With No Final Word on Cell Phone Link to Cancer, UCNI Specialists Re-state Call for Reasonable Precaution

CINCINNATI – Specialists at the Brain Tumor Center at the UC Neuroscience Institute and the Mayfield Clinic re-iterated their position that cell phone users should avoid placing the phones next to their head during conversation.

The specialists re-stated their position following the release of a statement by the International Agency for Research on Cancer (IARC), an arm of the World Health Organization, describing cell phone use as a possible cancer risk. The IARC placed the use of cell phones in the same category for cancer risk as 266 other environmental agents, including coffee, Styrofoam, lead, engine exhaust and chloroform.

A team of 31 scientists from 14 countries, including the United States, evaluated exposure data, studies of cancer in humans, studies of cancer in experimental animals, and mechanistic and other relevant data to reach their conclusion. They concluded that there appeared to be a positive association between wireless telephones and both glioma (a malignant brain tumor) and acoustic neuroma (a benign brain tumor). However, a cause and effect relationship has not been proven. In contrast, the evidence was inadequate to draw any conclusions for other types of brain tumors.

“We have always said that cell phone users should avoid placing the phone to their ear,” said John M. Tew, MD, Clinical Director of the UC Neuroscience Institute (UCNI) and a neurosurgeon with the Mayfield Clinic. “A wireless or remote receiver or a speaker setting should be used for frequent or extended conversations.”

Dr. Tew said the issue of children’s exposure to non-ionizing radiation from cell phones is especially important, and that researchers and practitioners at the Mayfield Clinic and UC Brain Tumor Center are following the issue closely and with concern. Children’s brains are exposed to higher radiofrequency energy from cell phones because their skulls are thinner. (The skull of a 10-year-old is a few millimeters thick; an adult’s is up to 15 millimeters thick.)

“We’re not ready yet to say that cell phones cause cancer, because it has not been proven,” Dr. Tew said. “At the same time, when you don’t know whether something is safe or unsafe, you take the proper precautions, and the proper precautions are to keep the phone away from your head.”

Concern over possible risks from low-level radiation emitted by cell phones, which are used by 4.6 billion people around the world, has grown in recent years with the publication of 30 epidemiological studies. In 2010, a large international study showed that individuals who were in the highest category of heavy cell phone use (reported average: 30 minutes per day over a 10-year period), showed a 40 percent increased risk for glioma.

“Your cumulative exposure to radiofrequency energy is a function of the number of calls you make, how long each call is, how far you are from the nearest base tower, the local cell phone traffic, the signal strength and whether you are using a hands-free unit or not,” noted Krishna Mohan, MD, a neurointensivist at UCNI who has spent considerable time reviewing the many studies of cell phone safety. “Cell phones, being possible carcinogens, need to be used sparingly by adults, and their use by children and teens, who have growing brains, needs to be restricted.”

UCNI specialists agree that more research is needed. Although one meta-analysis suggests an increased risk for long-term users of three tumors -- gliomas, acoustic neuromas and meningiomas -- on the side of the head where the cell phone is placed, another study recently published and used by the WHO Working Group does not suggest that gliomas are preferentially located in the parts of the brain with the highest radiofrequency fields from cell phones, according to Tania Carreon-Valencia, PhD, an epidemiologist with the UC Brain Tumor Center.

“Furthermore,” Dr. Carreon-Valencia said, “cumulative call time, duration of use, and the cell phone user’s listening ear were not consistently associated with the location of the gliomas. It is therefore necessary to conduct additional research.”

A new study, MobiKids, funded by the European Union, is investigating the risk of brain tumors from cell phone use in children and adolescents. Pending the availability of such information, the WHO recommends taking pragmatic measures to reduce exposure, such as hands-free devices or texting.

In 2010 the Acoustic Neuroma Association Board of Directors published a “cautionary alert” regarding cell phone usage and acoustic neuroma. The statement was endorsed by the ANA Medical Advisory Board, which is co-chaired by Dr. Tew and includes Philip Theodosopoulos, MD, a neurosurgeon with UC Brain Tumor Center and the Mayfield Clinic.

In response to the WHO’s statement, the UC Neuroscience Institute and Mayfield Clinic make the following recommendations:

• Avoid use of cell phones while driving and cycling, because the risk is comparable to the risk of driving under the influence of alcohol.
• Keep cell phones away from your head; a safe distance is at least 5 inches away from the skull.
• Use an air-tube headset, a remote receiver, or the phone’s speaker setting.
• Limit the use of cell phone in children to reduce exposure to the developing brain.
• Alternate sides and limit the duration of your calls.
• Text more, listen more, and talk less. Cell phones emit radiation when you talk or text, but not when you are receiving signals or messages.
• Don’t try to communicate when the signal is poor (e.g., in an elevator, building or rural area). Poor signals mean your cell phone needs to send stronger signals to the tower, which results in a higher level of radiation.
• Don’t use the “radiation shield.” Radiation shields such as antenna caps or keypad covers reduce the connection quality and force the machine to emit higher radiation to deliver a stronger signal.