Radiation

radiation
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Terms in this set (12)
radiation
energy in the form of electro magnetic waves or accelerated atomic particles, traveling in the air
non- ionizing radiation
enough energy to excite atoms, but not enough to remove an electron from the nucleus

soundwaves, visible light, microwaves, radiofrequency
ionizing
energy in the form of waves of particles that have enough energy to remove electrons from an atom

cosmic rays-- greater at higher elevations

natural and human caused radioactive decay
-nuclear reactors and weaponry, ct scans, x-rays
ionizing health effects
any molecule may be altered by radiation, but DNA is the most critical biological target

gamma and xrays can be sparsely ionizing --lesions in DNA are reparable

alpha are densely ionizing--lesions in DNA are less reprable
Acute ionizing health effect
high levels of radiation in brief period

damage accumulates faster than can be repaired

skin burns (superfiscial to thickness) including destruction of bone
radiation sickness
symptoms can occur immediately or over a few days, weeks, or months

bone marrow and gastrointestinal tract are sensitive

children and fetuses are most likely to be severely injured by radiation
chronic radiation exposure effects
low level- whole body dose uner 1sv (cell mutations to chromosomes)

birth defects (organogenesis, disturbances in development, increased risk of leukemia and other cancers)

cancer (leukemia, bone, lunch, thyroid cancer)
ionizing protection and prevention
1. only justifiable if it produces a benefit
2. in any such beneficial activity, the dose should be kept AS LOW AS REASONABLY ACHIEVABLE (ALARA)
3. there should be dose limits on any exposure to ionizing radiation

international atomic energy agency recommends the effective dose not exceed .005Sv

Time:


distance:


shielding:
alpha radiation
energetic, positive charged

2 protons, 2 neutrons

emitted from heavy radioisotopes-- uranium 238, radium 226, polunium 210

heavy mass- move slow through air

lack energy to penetrate dead layer of skin

hazard if inhaled or ingeste
beta radiation
fast moving electrons emitted from nucleus during radioactive decay

lower relative mass, enrgy than alpha particles

greater relative penetration than alpha particles

stopped by thin layer of clothing or few mm of material

burns when absorbed by skin

greater risk for internal harm
gamma radiationneutron to proton ratio is too great in nucleus and causes instability weightless packets of erngy-photons often accompany/follow alpha and beta shield with several feet of concrete or lead hazard for entire body x-rays similar but occur outside nucleusnon ionizing radiationcomes from uv light but health effects to skin and eyes-- sunlight, sun lamps, tanning beds, welding arcs, lasers, fluorescent -sunburn, skin cancers, photokeratitis, photo conjunctivities infrared radiation -furnace, ovens, welding arcs, molten glass and metal, heating lamps -burns of skin and cataracts microwave and radiofrequency -radar, tv, radio, cells, heating and welding -burns to dermal and subcutaneous tissues and potential damage to dna extremely low frequency electromagnetic fields -solar activity, thunderstorms -high exposures cause alteration in melatonin secretion, endocrine activity, immune response, cardiac fibrillation -long term can cause cancer, reproductive disorders