The study, conducted by the London-based Institute of Cancer Research, and published this week on the British Journal of Cancer's Web site, found no increased risks of a rare benign tumor in the nerve that links the ear to the brain.
Researchers questioned 678 patients already diagnosed with the tumor acoustic neuroma and 3,553 who did not have it, about their cell phone use. There was no increased risk of tumor associated with using the phones for at least 10 years.
Retrospective questionnaires are not considered the most accurate method of determining a link between behavior and disease. Several previous studies, using more rigorous methods, have also found no evidence that the phones pose a health risk.
However, scientists have said it may not be a good idea for children to use the phones for long periods because their brains are still developing. Also, it is too early to tell what the effects of long-term use will be on adults, reports the AP.