1. NONIONIZING RADIATION ….. a discussion of the health hazards associated with exposures to non- ionizing radiation

2. The Electromagnetic Spectrum u A name scientists give to a number of different types of radiation when they talk about them as a group u Energy is proportional to frequency and is inversely proportional to wavelength u Inherent energy defines the transition between ionizing and non-ionizing radiations

3. Electromagnetic Spectrum u Electromagnetic Spectrum Video Clip Electromagnetic Spectrum Video Clip Source: http://imagine.gsfc.nasa.gov/docs/science/know_l2/emspectrum.html

4. THE NON-IONIZING RADIATIONS u RF, (RADIO FREQUENCY) u MICROWAVES u INFRARED u VISIBLE (LASER) u ULTRAVIOLET u AND BEYOND

5. ULTRAVIOLET u Types: UV-A, UV-B, and UV-C u SOURCES: sun, mercury lamps, welding, lasers, pest control (fly lamps), fluorescent lighting u Target Organs: skin, eyes, immune system

6. Biological Effect [UV] u Aging of the skin u Reddening of the skin (erythema) u Skin cancer upon prolonged exposures u Corneal injury u Photosensitization (with some chemicals) u Benefits – Induces production of Vitamin D in skin

7. LASERS u Light Amplification by Stimulated Emission of radiation (LASER) u COHERENT u MONOCHROMATIC u DIRECTIONAL

8. Biological Effects [LASERS] u Primarily to the eye –retinal injury is most significant u Secondarily to the skin

9. INFRARED u SOURCES: most are thermal sources (plasma torches, halogen lamps) u Target Organs: skin and eyes

10. Biological Effects [Infrared] u Primarily thermal in nature u Skin: heats/burn surface of the skin and tissues immediately below u Eyes: Can damage retina and cornea, cause cataracts infrared: u Easiest to avoid: you can see it & feel it

11. MICROWAVE APPLICATIONS u Sources: –Radar –Communications. –TV –Heating and drying –Air traffic control

12. Biological Effects [Microwaves] u Primarily thermal effects u Capable of forming cataracts u CNS, biochemical changes? u Secondary problems (pace-makers, etc.)

13. RADIO FREQUENCY u What we said about microwaves applies for RF waves also, only to a lesser degree. u This area, and the extra low frequency (ELF) energies are getting a lot of attention right now!