csua.org/u/cyb -> www.hiroshima-is.ac.jp/Hiroshima/radiation.htm
even unborn babies were affected by radiation from the atomic bomb? that it would require a wall of concrete over 150 cm thick to complete ly shield you from the radiation from the atomic bomb?
Frequently Asked Questions About the Atomic Bomb The Effects of Radiation Exposure to Humans by: Sarah Skaer, Grade 8 A-bomb related Radiation is classified in two main categories: initial radiation and res idual radiation. Initial radiation was exposed approximately one minute from the explosion. Residual radiation stayed in the air and soil, even after a long period of time after the explosion. The people who were the closest to the hypocenter (the exact place where the bomb exploded) rec eived the highest amount of radiation. Even if a person entered Hiroshim a and came within 1 km of the hypocenter, one hundred hours after the bo mbing, the person would have been exposed to residual radiation. People who were protected somehow from the bomb blast, by a wall for example, d ecreased their risk of receiving radiation. Both types of radiation took place when the bomb dropped, and both are deadly. If someone received more than this dosage of radiation, there w ould be no chance for the person to stay living. Effect of Radiation on The Human Body (unit: gray (Gy)) 100 Unconsciousne ss or coma. Death within several hours 10 Destruction of bone marrow, severe radiation sickness and reduced whit e blood cells and platelets, Death within 30 days 1 Nausea and vomiting. A few hours after the explosion, vomit ing was the first sign that acute radiation that occurred. Later, either ones hair would fall out, or it will just become more thin and eventual ly break off. Vomiting, diarrhea, number of blood cells reduced, bleedin g, hair loss, temporary sterility in males, and lens opacity are the mos t common symptoms that resulted from acute radiation syndrome. The severity of the symptom, depended upon the dose of radiation received . If the dose of radiation was small, then not all of these symptoms tha t were described above occurred. If the dose of the radiation was high, one could die of bone marrow disorder in two or more months after the ex posure. Obviously, if the radiation dose is extremely high, then the per son would die sooner: in ten to twenty days, probably because of intesti nal disorder. Other types of radiation include neutron rays, alpha rays, beta rays, and gamma rays. Descriptions of each type of radiation are as follows: alph a rays are made up of two protons and two neutrons. An alpha ray is a very weak form of radiation, and can be blocked easily with a piece of paper. Beta rays are able to t ravel from 1 mm to about 1cm for phosphorus-32 in water. Gamma rays can go deep into a human body and have been mostly observed for cancer radio therapy. Neutrons are what triggers a nuclear chain reaction to explode an Atomic bomb. Neutrons hardly do any damage to cells, but they do caus e various kinds of damage to the human body. All of the types of radiation mentioned contrasts wit h one another, and all developed at some time during or after the A-bomb hit Hiroshima.
Brief definitions of these follow: Alpha rays A particle ray consisting of two protons and two neutrons (namely, a nucl eus of helium). Alpha rays are produced following spontaneous decay of c ertain radioactive atoms, such as radium, plutonium, uranium, and radon. Because of its large mass and positive charge, an alpha ray can usually pass only a short distance--less than 1 mm--in water. A single piece of paper can stop an alpha ray effectively. Therefore, health effects of a lpha-ray exposures appear only when alpha-emitting materials are ingeste d (ie, internal exposure). Beta ray A particle ray consisting of a fast electron whose mass is nearly 1/2000 of the mass of a proton or neutron. Beta rays are produced following spo ntaneous decay of certain radioactive materials, such as tritium (an iso tope of hydrogen), carbon-14, phosphorus-32, and strontium-90. Depending on its energy (ie, speed), a beta ray can traverse different distance s in water--less than 1 mm for tritium to nearly 1 cm for phosphorus-32. As with alpha rays, the major concern for health effects is after their ingestion (ie, internal exposure). Gamma ray An electromagnetic wave, a gamma ray is similar to ordinary visible light but differs in energy or wavelength. Sunlight consists of a mixture of electromagnetic rays of various wavelengths, from the longest, infrared, through red, orange, yellow, green, blue, indigo, and violet, to the sh ortest in wavelength, ultraviolet. A gamma ray's wavelength is far short er than ultraviolet (ie, it is far higher in energy). Gamma rays are p roduced following spontaneous decay of radioactive materials, such as co balt-60 and cesium-137. A cobalt-60 gamma ray can penetrate deeply into the human body, so it has been widely used for cancer radiotherapy. X ray X rays have the same characteristics as gamma rays, although they are pro duced differently. When high-speed electrons hit metals, electrons are s topped and release energy in the form of an electromagnetic wave. This w as first observed by Wilhelm Roentgen in 1895, who considered it a myste rious ray, and thus called it an X ray. X rays consist of a mixture of d ifferent wavelengths, whereas gamma-ray energy has a fixed value (or two ) characteristic to the radioactive material. Neutrons Neutron particles are released following nuclear fission (splitting of an atomic nucleus producing large amounts of energy) of uranium or plutoni um. In fact, it is neutrons that trigger the nuclear chain reaction to e xplode an atomic bomb. Neutrons hardly damage cells because they do not carry any electrical charge. However, the human body contains a large am ount of hydrogen (a constituent of water molecules that occupy 70% of th e human body), and when neutrons hit the nucleus of hydrogen, ie, a pr oton that is positively charged, the proton causes ionizations in the bo dy, leading to various types of damage. At equivalent absorbed doses, ne utrons can cause more severe damage to the body than gamma rays.
Information on RERF and its History by: Stephanie Ryan, Blake Wilson, Anna Song, Grade 7/8 The RERF program was started during the November of 1946 when President H arry Truman approved a directive to the national Academy of Sciences (NA S), and the National Research Council (NRC), to study the effects of rad iation on people. The NAS and the NRC received finding from the Atomic E nergy Commission (now called the Department of Energy). The NRS -NRC beg an the Atomic Bomb Casualty Commission (ABCC) during March of 1947 and b egan to conduct research the following year. The Japanese National Insti tute of Health became a partner in these research committees. In 1975, t his same committee developed a new research laboratory an called it the Radiation Effects Research Foundation (RERF). RERF scientists conduct research mainly in the categories of cancer and m olecular biology. They study people who were directly effected by The ra diation of the explosion, and work to help gain the better physical heal th of people over all. There was some controversy over the medical atten tion to the survivors of the bomb, and their study of people. They wante d to study the effects of radiation, but did not provide medical attenti on. They preformed surgeries to further their studies for nothing else. RERF studies cancer to receive evidence of the dose/cancer risk response patterns. They do this to study the mortality rate of non-cancer suffere rs. They also research information on the biological, genetic and enviro nmental effect and also study the impacts of carcinogenic (cancer causin g) and non-carcinogenic effects on the younger and more susceptible gene ration, versus the health of adults tested under the same conditions. In molecular biology, efforts are being made to monitor the rate of human populations' mutation rates. This is now becoming possible due to a dev elopment in the study of DNA, where it is now possible to detect a mutat ion on the level of nucleotide bases. They are trying to collect a numbe r of cells from both exposed an...
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