Non-ionizing radiation

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.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.

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Near ultraviolet, Visible light, infrared, microwave, radio waves, low frequency RF 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). Static fields do not radiate

	Source	Wavelength	Frequency	Biological Effects
UVC	Germicidal light	100 - 280 nm		Skin – Erythema, inc pigmentation; Eye – Photokeratitis (inflammation of cornea)
UVB	Tanning booth	280 - 315 nm		Eye – Photokeratitis (inflammation of cornea) Skin – Erythema, inc pigmentation Skin cancer, Photosensitive skin reactions, Production of vitamin D
UVA	Black light, sunlight	315 - 400 nm		Eye – Photochemical cataract Skin – Erythema, inc pigmentation
Visible Light	lasers, sunlight	400 - 780 nm		Skin photo-ageing, Skin cancer; Eye – Photochemical & thermal retinal injury
IR-A	lasers, remote controls	780 nm - 1.4 µm		Eye – Thermal retinal injury, thermal cataract; Skin burn
IR-B	lasers, long-distance telecommunications	1.4 µm - 3 µm	215 THz - 100 THz	Eye – Corneal burn, cataract Skin burn
IR-C	Far-infrared laser	3 µm - 1 mm	100 THz - 300 GHz	Eye – Corneal burn, cataract; Heating of body surface
Microwave	PCS phones, microwave ovens, cordless phones, motion detectors, radar, Wi-Fi	33 cm - 1 mm	1 GHz - 300 GHz	Heating of body surface
Radio Frequency Radiation	Cell phones, television, FM, AM, Shortwave, CB, cordless phones	3 Km - 33 cm	100 KHz - 1 GHz	Heating with ‘penetration depth’ of 10 mm, Raised body temperature
Low frequency RF	power lines	> 3 Km	< 100 KHz	Cumulation of charge on body surface Disturbance of nerve & muscle responses
Static Field	strong magnets, MRI	infinite	0 Hz	Magnetic - vertigo/nausea, Electric - charge on body surface

Ultraviolet radiation

• Biological effects
• Effects on the Skin

Burns

• Effects on the Eyes

Cataracts

• Other Hazards
• Occupational Exposure Standards
• Protection Against Overexposure
• Recommended Maximum Permissible Exposure Levels

Visible and infrared, lasers

• Biological effects
• Effects on the Skin
• Effects on the Eyes
• Other Hazards
• Occupational Exposure Standards

Microwave and radio frequency radiation

• Biological effects
• Effects on the Skin
• Effects on the Eyes
• Other Hazards
• Occupational Exposure Standards

Low frequency ELF

• Biological effects

• Effects on the Skin
• Effects on the Eyes
• Other Hazards

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.

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.

Studies in experimental animals have not shown a consistent carcinogenic or co-carcinogenic effects of exposures to ELF magnetic fields, and no scientific explanation has been established for the observed association of increased childhood leukaemia risk with increasing residential ELF magnetic field exposure.

More recently, there has been a similar review in America by the California Department of Health, finding that some, but not all, of the other implicated effects may well be sufficiently supported by the current scientific literature.

To one degree or another, all three of the DHS scientists are inclined to believe that EMFs can cause some degree of increased risk of childhood leukemia, adult brain cancer, Lou Gehrig’s Disease, and miscarriage.

They strongly believe that EMFs do not increase the risk of birth defects, or low birth weight.

They strongly believe that EMFs are not universal carcinogens, since there are a number of cancer types that are not associated with EMF exposure.

To one degree or another they are inclined to believe that EMFs do not cause an increased risk of breast cancer, heart disease, Alzheimer’s Disease, depression, or symptoms attributed by some to a sensitivity to EMFs.

All three scientists had judgments that were "close to the dividing line between believing and not believing" that EMFs cause some degree of increased risk of suicide.

For adult leukemia, two of the scientists are "close to the dividing line between believing or not believing" and one was "prone to believe" that EMFs cause some degree of increased risk.

For further reading on this area, read Electric_power_transmission#Health_concerns.

• Occupational Exposure Standards

Static fields

• Biological effects

• Effects on the Skin
• Effects on the Eyes
• Other Hazards
• Occupational Exposure Standards

See also

• Mobile phone radiation and health
• Ionizing radiation