nonionizing radiation ….. a discussion of the health hazards associated with exposures to non-...
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NONIONIZING RADIATION
….. a discussion of the health hazards associated with exposures to non-
ionizing radiation
The Electromagnetic Spectrum
A name scientists give to a number of different types of radiation when they talk about them as a group
Energy is proportional to frequency and is inversely proportional to wavelength
Inherent energy defines the transition between ionizing and non-ionizing radiations
Electromagnetic Spectrum
Electromagnetic Spectrum Video Clip
Source: http://imagine.gsfc.nasa.gov/docs/science/know_l2/emspectrum.html
THE NON-IONIZING RADIATIONS
RF, (RADIO FREQUENCY)
MICROWAVES INFRARED VISIBLE (LASER) ULTRAVIOLET AND BEYOND
ULTRAVIOLET
Types: UV-A, UV-B, and UV-C
SOURCES: sun, mercury lamps, welding, lasers, pest control (fly lamps), fluorescent lighting
Target Organs: skin, eyes, immune system
Biological Effect [UV]
Aging of the skin Reddening of the skin (erythema) Skin cancer upon prolonged exposures Corneal injury Photosensitization (with some chemicals) Benefits – Induces production of Vitamin D
in skin
LASERS
Light Amplification by Stimulated Emission of radiation (LASER)
COHERENT MONOCHROMATIC DIRECTIONAL
Biological Effects [LASERS]
Primarily to the eye – retinal injury is most significant
Secondarily to the skin
INFRARED
SOURCES: most are thermal sources (plasma torches, halogen lamps)
Target Organs: skin and eyes
Biological Effects [Infrared]
Primarily thermal in nature Skin: heats/burn surface of the skin and
tissues immediately below Eyes: Can damage retina and cornea, cause
cataracts infrared: Easiest to avoid: you can see it & feel it
MICROWAVE APPLICATIONS Sources:
– Radar
– Communications.
– TV
– Heating and drying
– Air traffic control
Biological Effects [Microwaves]
Primarily thermal effects Capable of forming cataracts CNS, biochemical changes? Secondary problems (pace-makers, etc.)
RADIO FREQUENCY
What we said about microwaves applies for RF waves also, only to a lesser degree.
This area, and the extra low frequency (ELF) energies are getting a lot of attention right now!