To find out about the state of research on the link between phones and cancer, we spoke with Jonathan Samet, dean of the Colorado School of Public Health and an expert in phone radiation who led a World Health Organization working group on the subject. In 2011, the WHO group deemed phone radiation “possibly carcinogenic,” which is less certain than other classifications, but isn’t an outright “no” either. Six years later, Samet said the evidence in either direction is still mixed and that for the time being, there remains “some indication” of risk.
A 2010 review stated that "The balance of experimental evidence does not support an effect of 'non-thermal' radiofrequency fields" on the permeability of the blood-brain barrier, but noted that research on low frequency effects and effects in humans was sparse.[4] A 2012 study of low-frequency radiation on humans found "no evidence for acute effects of short-term mobile phone radiation on cerebral blood flow".[5][6]
Radiofrequency radiation is a form of electromagnetic radiation. Electromagnetic radiation can be categorized into two types: ionizing (e.g., x-rays, radon, and cosmic rays) and non-ionizing (e.g., radiofrequency and extremely low frequency, or power frequency). Electromagnetic radiation is defined according to its wavelength and frequency, which is the number of cycles of a wave that pass a reference point per second. Electromagnetic frequencies are described in units called hertz (Hz).