Is your cell phone hurting your brain? Researchers are studying that very question in an effort to determine whether heavy and frequent cell phone use leads to an increase in brain cancer. Concern about cell phone safety centers on the device's built-in antenna, which emits electromagnetic waves. Thus far, various medical studies have yet to prove any significant increase in brain cancer among cell phone users. However, since widespread cell phone use is a relatively new phenomenon, such studies only cover short-term use. As such, the long-term effects have yet to be determined.