Cell phone study shows no increased risk, but ...

GENEVA – Cancer Digest – Researchers conducting the largest international study to date of the risks of brain cancers from cell phone use have found no elevated risk for glioma or meningioma, the two most common forms of the disease.

The INTERPHONE study is a set of international population studies begun in 2000. It involved more than 10,000 people interviewed at 16 cancer centers in 13 countries and focused on tumors in younger people, 30–59 years of age – the population group expected to have had the highest prevalence of mobile phone use over the past decade.

Among them there were 2,708 diagnosed with glioma, the most deadly form of brain cancer, and 2,409 cases of meningioma, a benign tumor that can become malignant. When they compared these people to carefully matched cellphone users who did not have cancer they found no statistically significant difference between the two groups.

“Overall, no increase in risk of glioma or meningioma was observed with use of mobile phones,” the researchers wrote. “There were suggestions of an increased risk of glioma at the highest exposure levels, but biases and error prevent a causal interpretation. The possible effects of long-term heavy use of mobile phones require further investigation.”

Published in the current issue of International Journal of Epidemiology, the researchers emphasized that this study is not the definitive study people have sought for so long. They cite the 40 percent greater risk of glioma suggested by the data for people using their phones over 1,640 hours during the 10-year study as compared to similar people without cancer, and note that in the intervening years since the study was conducted, cell phone use has increased substantially.

The majority of participants in the study were not categorized as heavy mobile phone users by today's standards. The median lifetime cumulative call time was around 100 hours, with a median of 2 to 21/2 hours of reported use per month. The heaviest 10 percent of users were those with 1,640 hours of use spread out over 10 years, which corresponds to about a half-hour per day.

Today, mobile phone use has become much more prevalent and it is not unusual for young people to use mobile phones for an hour or more a day. At the same time this increasing use is tempered, by the lower emissions, on average, from newer technology phones, and the increasing use of texting and hands-free operations that keep the phone away from the head.