Radiation is energy that comes from a source and travels through space. For example, an electric heater operates by heating metal wires and the wires radiate that energy as heat (infrared radiation).
Radio frequency radiation is a type of electromagnetic radiation, which is a combination of electric and magnetic fields that move through space together as waves. Electromagnetic radiation falls into two categories:
|Electromagnetic Radiation||Examples||Sources Include:|
|Non-ionizing radiation: Routine exposure to non-ionizing radiation is generally perceived as harmless to humans||
||Light bulbs, computers, Wi-Fi routers, portable phones, cell phones, Bluetooth devices, FM radio, GPS, and broadcast television|
|Ionizing radiation: High energy radiation with the potential for direct cellular and DNA damage||
||X-ray machines, radioactive material, nuclear fission, nuclear fusion, and particle accelerators|
Generally, when people hear the word radiation, they’re thinking of ionizing radiation, like X-rays and gamma rays. Ionizing radiation carries enough energy to break chemical bonds, knock electrons out of atoms, and cause direct damage to cells in organic matter. In fact, ionizing radiation carries more than a billion times more energy than does non-ionizing radiation. A little ionizing radiation can be used to produce x-ray images for diagnosis. A lot of ionizing radiation is needed to kill cancer cells in radiation therapy.
By contrast, non-ionizing radiation does not have enough energy to break chemical bonds or strip electrons from atoms. Scientific consensus shows that non-ionizing radiation is not a carcinogen and, at or below the radio frequency exposure limits set by the FCC, non-ionizing radiation has not been shown to cause any harm to people.
Cell phones emit low levels of non-ionizing radiation while in use. The type of radiation emitted by cell phones is also referred to as radio frequency (RF) energy. As stated by the National Cancer Institute, "there is currently no consistent evidence that non-ionizing radiation increases cancer risk in humans. The only consistently recognized biological effect of radiofrequency radiation in humans is heating."
For a more detailed description of radio frequency radiation, see Microwaves, Radio Waves, and Other Types of Radiofrequency Radiation from the American Cancer Society.
For more information about the electromagnetic spectrum, see NASA’s Tour of the Electromagnetic Spectrum.
For more information about radio frequency safety, see the FCC’s RF Safety FAQ.