Non-ionizing radiation (or, esp. in British English, non-ionising radiation) refers to any type of electromagnetic radiation that does not carry enough energy per quantum to ionize atoms or molecules — that is, to completely remove an electron from an atom or molecule.^[1]Instead of producing charged ions when passing through matter, the electromagnetic radiation has sufficient energy only for excitation, the movement of an electron to a higher energy state. Nevertheless it is known to cause biological effects^[2]. British English (BrE) is a broad term used to distinguish the forms of the English language used in the United Kingdom from forms used elsewhere. ... It has been suggested that this article or section be merged with light. ... In physics, a quantum (plural: quanta) is an indivisible entity of energy. ... ... e- redirects here. ... Properties In chemistry and physics, an atom (Greek ἄτομος or átomos meaning indivisible) is the smallest particle still characterizing a chemical element. ... In science, a molecule is a group of atoms in a definite arrangement held together by chemical bonds. ...

Visible light, near ultraviolet, infrared, microwave, radio waves, and static fields are all examples of non-ionizing radiation. Visible and near ultraviolet may ionize some molecules or accelerate radical reactions. The light from the Sun that reaches the earth is largely composed of non-ionizing radiation, with the notable exception of some ultraviolet rays. However, most ionizing radiation is filtered out by the atmosphere (see Earth's atmosphere). The optical spectrum (light or visible spectrum) is the portion of the electromagnetic spectrum that is visible to the human eye. ... Note: Ultraviolet is also the name of a 1998 UK television miniseries about vampires. ... Image of two girls in mid-infrared (thermal) light (false-color) Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than that of visible light, but shorter than that of radio waves. ... Microwaves are electromagnetic waves with wavelengths longer than those of terahertz (THz) frequencies, but relatively short for radio waves. ... For other uses, see Radio (disambiguation). ... In chemistry, radicals (often referred to as free radicals) are atomic or molecular species with unpaired electrons on an otherwise open shell configuration. ... The Sun is the star at the center of the Solar System. ... UV redirects here. ... Layers of Atmosphere - not to scale (NOAA)[2] Earths atmosphere is a layer of gases surrounding the planet Earth and retained by the Earths gravity. ...

Health risks

Non-ionizing radiation hazard sign

Lower energy radiation is not mutagenic. The use of this type of radiation in medical fields and everyday life poses fewer health risks than ionizing radiation in forms such as X-rays. Strong nonionizing radiation has a heating effect. Spectrum of a fluorescent black light source. ... The optical spectrum (light or visible spectrum) is the portion of the electromagnetic spectrum that is visible to the human eye. ... Image of two girls in mid-infrared (thermal) light (false-color) Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than that of visible light, but shorter than that of radio waves. ... Image of two girls in mid-infrared (thermal) light (false-color) Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than that of visible light, but shorter than that of radio waves. ... Image of two girls in mid-infrared (thermal) light (false-color) Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than that of visible light, but shorter than that of radio waves. ... Microwaves are electromagnetic waves with wavelengths longer than those of terahertz (THz) frequencies, but relatively short for radio waves. ... In biology, a mutagen (Latin, literally origin of change) is an agent that changes the genetic information (usually DNA) of an organism and thus increases the number of mutations above the natural background level. ... Radiation hazard symbol. ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz...

Recently, in 2001, extremely low frequency (ELF) magnetic fields have been identified as possibly carcinogenic (Group 2B) by the IARC. There are consistent statistical associations of high level residential magnetic fields with a doubling of risk of childhood leukaemia. The threshold is at 0.4 microtesla; less exposure to residential ELF does not increase the risk for leukaemia. A small forest elf (älva) rescuing an egg, from Solägget (1932), by Elsa Beskow An elf is a mythical creature of Germanic mythology and Germanic paganism which still survives in northern European folklore. ... The International Agency for Research on Cancer (IARC, or CIRC in its French acronym) is an intergovernmental agency forming part of the World Health Organisation of the United Nations. ... Leukemia (leukaemia in Commonwealth English) is a group of blood diseases characterized by malignancies (cancer) of the blood-forming tissues. ... The tesla (symbol T) is the SI derived unit of magnetic flux density (or magnetic induction). ...

However pooled analyses of data from a number of well-conducted studies show a fairly consistent statistical association between a doubling of risk of childhood leukaemia and power-frequency (50 or 60 Hz) residential ELF magnetic field strengths above 0.4 microtesla. In contrast, no consistent evidence was found that childhood exposures to ELF electric or magnetic fields are associated with brain tumours or any other kinds of solid tumours. No consistent evidence was found that residential or occupational exposures of adults to ELF magnetic fields increase risk for any kind of cancer.^[3]

See also

• Mobile phone radiation and health
• Ionizing radiation

A Greenfield-type tower used in base stations for mobile telephony A modern mobile phone (Samsung) Mobile phone radiation and health concerns have been raised, especially following the enormous increase in the use of wireless mobile telephony throughout the world (as of August 2005, there were more than 2 billion... Radiation hazard symbol. ...

References