In recent years, there has been controversy about the relationship between cell phone radiation and brain tumors (especially gliomas). Some statistics show that the incidence of malignant brain tumors in the United States decreased from 6.5 to 6.2 per 100,000 from 1992 to 2007, but the incidence in children increased from 13.4 to 18.2 per 100,000 (in 1995) (in 2008). The increasing use of cell phones by adolescents and children during the same period, with more than 4/5 children and adolescents often sleeping with their cell phones, suggests that cell phone use may be associated with glioma. The effects of electromagnetic radiation from cell phones may be greater for children because they have thinner skulls, smaller heads, higher brain conductivity, and are developing. On May 31, 2011 the International Agency for Research on Cancer (IARC) specified RF EMF as a probable human carcinogen (Group2B). A recent meta-analysis examined the relationship between long-term cell phone use and glioma in three dimensions: time, site, and tumor grade, and showed that ipsilateral long-term cell phone use was positively associated with the risk of glioma, with cell phone use increasing the risk of low-grade glioma and significantly increasing the risk of long-term use (≥10 years); however, no significant association was seen with high-grade glioma. However, the quality and quantity of the current evidence are mixed, and there is a need for prospective, large-sample, cross-ethnic, high-quality studies of long-term ipsilateral cell phone use.