Updated results from a large study conducted in Denmark found no increased risk of brain tumors among long-term cell phone users. These results were published in the British Medical Journal.
Cell phones emit radio waves. Radio waves are a type of low-frequency (non-ionizing) electromagnetic radiation. Exposure to high levels of this type of radiation can heat body tissue, but studies suggest that the amount of energy produced by cell phones is too low to produce significant heating.
Although concerns have been raised about possible links between cell phones and cancers of the brain and other parts of the head and neck, studies have not found any consistent link. Nevertheless, it’s not yet possible to draw firm conclusions about the health effects of cell phones, and research on this topic continues.
The current study included information about more than 10,000 people with brain tumors and more than 358,000 cell phone users.
- Long-term cell phone use (13 years or more) did not increase the risk of brain tumors overall, nor was there an increased risk in parts of the brain that were closest to where a cell phone would be held.
- Separate analyses of meningioma and glioma also failed to find links with cell phone use.
Information was not available about the amount of time each person spent on the phone, so the researchers were not able to assess the effects of very heavy cell-phone use. Overall, however, the results suggest that cell phone for more than a decade use does not increase the risk of brain tumors.
An accompanying editorial notes that although these results are reassuring, additional research is warranted.
 National Cancer Institute Fact Sheet. Cell Phones and Cancer Risk. Accessed October 21, 2011
 Frei P, Poulsen AH, Johansen C, Olsen JH, Steding-Jessen M, Schuz J. Use of mobile phones and risk of brain tumours: update of Danish cohort study. BMJ. 2011; 343:d6387