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!