EESA10H3 Lecture Notes - Lecture 6: Microwave Oven, Cosmic Ray, Background Radiation
20 Mar 2019
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Document Summary
Radiation and human health: we cannot escape radiation, background radiation natural radioactivity in the earth and by cosmic rays from outer space. Cannot be controlled: everyone is exposed, manmade radiation electronic products: Ionized radiation: high energy, short wavelength, non-ionized radiation, low energy, long wavelength. How does ionized radiation cause health effects: radioactive material that decay spontaneously produce ionizing radiation. Strip away electrons from atoms (create two charged ions) Breaks some chemical bonds: alpha, beta particles, gamma and x-rays (differ in the amount of energy they have) Health effects from exposure to radionuclides: stochastic health effects chronic, long term, low level of exposure. Increase levels of exposure make these effects more likely to occur but do not influence the type or severity of the effect. The chance of getting cancer is higher if the dose is higher but severity of the symptoms does not depend on the dose: non-stochastic health effects acute, short term, high level of exposure.
