Wide concerns have been raised that the use of cell phones could increase brain tumors. This paper systematically reviews the scientific evidence regarding the associations between cell phone use and brain tumors. The authors’ review suggests two conclusions. First, it is still controversial in regard with the significant associations between cell phone use and increased risk of brain tumors. Second, there exists extensive evidence that the amount of exposure to cell phone radiation plays a key role in determining the significant associations between cell phone use and gliomas, acoustic neuroma, and meningiomas. In general, those who use cell phones for more than ten years, using cell phones more than 20 minutes per day, or cumulative call time for more than 700 hours, or RF-EMF absorption for more than 3000 joules/kg have higher risks to develop brain tumors, whereas those who use cell phones for less than one year have lower risks.
