is3_111 - Someone living at sea level will, on average,...

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Unit 5 Other Radiological Hazards 5-3 NATURAL SOURCES Natural sources of radiation that individuals are exposed to routinely come from either cosmic radiation or terrestrial radiation . Cosmic Radiation Just under half of man’s exposure to external natural radiation comes from cosmic rays. Most of these originate deep in interstellar space, however, some are released from the sun during solar flares. They irradiate the earth and interact with the atmosphere to produce further types of radiation and radioactive materials. This source of radiation is always present. However, it affects some parts of the earth more than others. The poles receive more than the areas or the earth near the equator because the earth’s magnetic field diverts the radiation. More importantly, however, the level of exposure to cosmic radiation increases with altitude, since there is less air as altitude increases to act as a shield.
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Unformatted text preview: Someone living at sea level will, on average, receive a dose or about 300 microsievert of cosmic radiation every year, while an individual living above 2,000 meters will receive several times as much. Cosmic Radiation Increases with Altitude A trip from New York to Paris would expose a passenger to about 50 microsievert in addition to whatever cosmic radiation he would be exposed to at home or work. The more frequently an individual flies, especially over long distances, the more additional dose from cosmic radiation he or she is exposed to. For this reason, there are requirements limiting the number of long flights that airline personnel can fly in any year to control the total additional dose these individuals receive from cosmic radiation....
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This note was uploaded on 01/29/2010 for the course MPA mpa1 taught by Professor Scotts during the Spring '10 term at Acton School of Business.

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