EESA10H3 Lecture Notes - Lecture 6: Radiography, Radon, Cosmic Ray
20 Apr 2016
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Document Summary
Background radiation natural radioactivity in the earth and by cosmic ray from outer space (can not be controlled) Manmade radiation electronic products: x-ray machine, xray diagnostic, television sets, microwave, lasers. Most radiation comes from radon gas from the ground. For artificial sources: medical radiation is the highest. Health: radioactive material that decay spontaneously produce ionizing radiation o o o o o o o o. Strip away electron from atom (create two charged ions) Alpha, beta, gamma and x-ray (differ in amount of energy) Stochastic health effect (chronic) - long term, low level of exposure, increase level of exposure makes these effect more likely to occur but do not influence type or severity of the effect. Teratogenic (fetus more sensitive in 8-15 week, smaller head and brain, poorly formed eyes and mental retardation). Non-stochastic health effects (acute) short term high level exposure, increase level of exposure makes these effect more severe.
