000			01882nam a2200193Ia 4500
003			RRU
005			20230412134430.0
008			210901b ||||||||| ||||||| 0|eng|d
020			_a9788171394043 _cRs.800.00
040			_aRRU _beng
041			_aEng.
082			_a363.738 _bSAL
245		0	_aNuclear and thermal pollution
260			_aJnanada Prakashan _b2010 _cNew Delhi,India
300			_a221p.
520			_aNuclear pollution is caused due to the addition, through activities of man, of ionizing radiations to the environment giving people an exposure to more of such radiations than they normally would experience. Radiation is able to permeate the universe, the solar system, and the earth. The surface of the planet would get bombarded with radiation from the sun so intense that life would be in danger if it were not for the atmosphere that surrounds the earth. The atmosphere is able to screen out much of the sun's radiation, including most of that which would be lethal to life. Cosmic rays, coming from outer space at high velocity are able to strike the earth continually and penetrate deeply into the surface. Naturally occurring radioactive elements are found in the rocks, water, and air and in all living organisms. Some of the incoming radiation gets trapped by the earth's magnetic field. The far-reaching portion of the atmosphere, called the magnetosphere, is having an area of high-energy radiation called the Van Alien region. It is roughly doughnut shaped, extending from about 500 miles above the earth at the equator to an altitude of about 40,000 miles. The Van Alien region was at first thought to present a major obstacle to space travel, but further studies revealed that astronauts would pass through the zones of high radiation quickly and that precautions could be taken to disallow excessive exposure.
650			_aSecurity
942			_2ddc _cBK
999			_c2163 _d2163