It has become one of the most controversial questions in cancer medicine: Can using a cell phone cause brain tumors? The federal government and the mobile-phone industry have maintained that there is no conclusive data to support a link between cell-phone radiation and cancer, but a growing band of scientists are skeptical, suggesting that the evidence that does exist is enough to raise a warning for consumers before mass harm is done.
What scientists and regulators need is truly conclusive scientific evidence. Enter Interphone, a $24 million long-term study that matched rates of brain cancer with cell-phone use among more than 12,000 participants in 13 countries. The long-awaited report whose findings were finally released on Monday after years of delay is by far the most comprehensive look at the issue to date, and was designed to provide the final word on the debate.
Unfortunately, the results turned out to be anything but clear. The study, which will be published this week in the International Journal of Epidemiology, found that, overall, there is no clear connection between cell-phone use and brain cancer. “An increased risk of brain cancer is not established from the data from Interphone,” says Dr. Christopher Wild, director of the International Agency for Research on Cancer, which helped coordinate the study.
But upon closer inspection, the results were checkered: the 10% of people who used their phones most often and for the longest period of time 30 minutes a day or more on average for at least 10 years had a substantially higher risk of developing some form of brain cancer than those who didn’t use a mobile phone at all. Meanwhile, people who used their cell phones infrequently had a lower risk of developing some brain tumors than those who exclusively used corded telephones as if mobile phones in small doses might offer some protection from brain cancer.