Units of measurement The rem is the unit used to measure radiationdosage. It represents the amount of radiation neededto produce a particular amount of damage to livingtissue. The total dose of rems determines how muchharm a person suffers. At Hiroshima and Nagasaki,people received a dose of rems at the instant of theexplosions, then more from the surroundings and, inlimited areas, from fallout. Fallout is composed ofradioactive particles that are carried into the upperatmosphere by a nuclear explosion and thateventually fall back to the earths surface.
Effects of radiation exposure Just 25 rems causes some detectable changes in blood,doses to near 100 rems usually have no immediateharmful effects. Doses above 100 rems cause the firstsigns of radiation sickness including. Those arenausea, vomiting, headache and some loss of white bloodcells.Doses of 300 rems or more cause temporary hair loss, butalso more significant internal harm, including damage tonerve cells and the cells that line the digestive tract.Severe loss of white blood cells, which are the bodysmain defense against infection, makes radiation victimshighly vulnerable to disease.
Radiation also reduces production of blood platelets,which aid blood clotting, so victims of radiation sicknessare also vulnerable to hemorrhaging. Half of all peopleexposed to 450 rems die, and doses of 800 rems or moreare always fatal. Besides the symptoms mentionedabove, these people also suffer from fever and diarrhea.As of yet, there is no effective treatment--so death occurswithin two to fourteen days. In time, for survivors,diseases such as leukemia, lung cancer, thyroid cancer,breast cancer, and cancers of other organs can appeardue to the radiation received.
Radiation exposure of reality・Nagasaki and Hiroshima The nuclear power bomb was dropped to Hiroshima andNagasaki in World War Ⅱ. Many people at Hiroshima andNagasaki died not directly from the actual explosion, butfrom the radiation released as a result of theexplosion. The survivors have suffered physically fromcataracts, leukemia and other cancers, malformedoffspring, and premature aging, and also emotionally,from social discrimination. Within a few months of thenuclear explosions, leukemia began to appear among thesurvivors at an abnormally high rate.
・Chernobyl Chernobyl accident is the most famous nuclearaccident. The radioactive release was equivalent to tenHiroshimas. In fact, since the Hiroshima bomb was air-burst--no part of the fireball touched the ground--theChernobyl release polluted the countryside much morethan ten Hiroshimas would have done. Many people diedfrom the explosion and even more from the effects of theradiation later. Still today, people are dying from theradiation caused by the Chernobyl accident. Theestimated total number of deaths will be 16,000.
Medical treatment There is currently no effective medical treatment forradiation doses. The case of the Japanese boymentioned above illustrates an important fact aboutradiation sickness. The boy had probably received a doseof 450 rems or more, yet his symptoms were about thesame as those of a person who received about 300 rems.Medical science has no way of telling the differencebetween people who have received fatal doses and willdie despite all efforts and others who received lessradiation and can be saved. Treatment for the ones thatcan be saved includes blood transfusions and bone-marrow transplants. Bone-marrow transplants rejuvenatethe supply of white blood cells which was affected by the