Residual and Initial Radiation and its Effects Then and in the Future

Percent of Fatalities from stated conditions from the Hiroshima Bomb. (Peace Memorial Museum)

Terms To Know Before Reading On:

• ra·di·a·tion   n. 1. The act or process of radiating: the radiation of heat and light from a burning body. 2. Physics. a. Emission and propagation of energy in the form of rays or waves. b. Energy radiated or transmitted in the form of rays, waves, or particles. c. A stream of particles or electromagnetic waves emitted by the atoms and molecules of a radioactive substance as a result of nuclear decay. (American Heritage Dictionary)
• Alpha rays - A particle ray consisting of two protons and two neutrons. Alpha rays are produced following spontaneous decay of certain 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 alpha-ray exposures appear only when alpha-emitting materials are ingested (i.e., 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 spontaneous decay of certain radioactive materials, such as tritium (an isotope of hydrogen), carbon-14, phosphorus-32, and strontium-90. Depending on its energy (i.e., speed), a beta ray can traverse different distances 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 (i.e., 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 shortest in wavelength, ultraviolet. A gamma ray's wavelength is far shorter than ultraviolet (i.e., it is far higher in energy). Gamma rays are produced following spontaneous decay of radioactive materials, such as cobalt-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 produced differently. When high-speed electrons hit metals, electrons are stopped and release energy in the form of an electromagnetic wave. This was first observed by Wilhelm Roentgen in 1895, who considered it a mysterious ray, and thus called it an X ray. X rays consist of a mixture of different 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 plutonium. In fact, it is neutrons that trigger the nuclear chain reaction to explode an atomic bomb. Neutrons hardly damage cells because they do not carry any electrical charge. However, the human body contains a large amount of hydrogen (a constituent of water molecules that occupy 70% of the human body), and when neutrons hit the nucleus of hydrogen, i.e., a proton that is positively charged, the proton causes ionizations in the body, leading to various types of damage. At equivalent absorbed doses, neutrons can cause more severe damage to the body than gamma rays.
• Initial Radiation - Radiation when exposed immediately at the time of explosion.
• Residual Radiation - Radiation that was absorbed in the soil and or air and stayed there for a long period of time after the exposure of the explosion. (i.e. If a person entered Hiroshima and came within 1 km of the hypocenter, one hundred hours after the bombing, the person would have been exposed to residual radiation.)

  (Radiation Effects Research Foundation)

     In a brilliant flash of light thousands were encased in searing heat and electromagnetic waves and in a  few breathless moments chaos ascended from the deepest depths of Hades. Black lifeless bodies littered the streets, some tangled in telephone lines others frozen in fear as they tried to run away from the light.  Thousands were killed or injured, many were left dying in the streets, crying out in pain for mercy.   Victims with faces melted shut, backs scorched, boiled bodies, and remnants of appendages waited in long lines for help or lied in the streets calmly waiting for death to embrace them.  Calculated in units known as grays (Gy) radiation, either initial or residual, was a painful killer. If the radiation dosage advanced higher than seven grays a person was turned away and left to wait out the rest of his or her's short life.  In most cases, like that of Sadako Sasaki, one of the most famous Hiroshima Bombing victims, many of these victims die in hospital wards filled with people suffering from the "Atom Bomb Disease", Leukemia.  Watching their white blood cell count rise and their gray count accelerate, these patients slowly and painfully wait for death.  But not all victims of these bombings died or were injured from nuclear radiation because shortly after the bombing a monsoon washed away the radiation that contaminated the land.  Unfortunately the Japanese people were still being affected from the emission. The effects of radiation on humans differ greatly depending on the dose of radiation received and whether the exposure to radiation is slow and enduring, or colossal and instantaneous. A enormous swift dose of radiation (over 7 grays or 700 rads [the equivalent of 7 joules per kilogram]) causes cell death, and effects are instantaneous (within hours, days, or weeks). Prolonged exposure allows a little bit restoration over exposure period even when the total dose is high so is normally better tolerated. Doses high enough to cause acute effects will be less likely to repair themselves during dosage, if at all. Doses low enough (below 7 joules per kilogram) to steer clear of cell damage still have the ability to induce mutations that may be detected clinically sometime in the future and could potentially be passed on through defective genes.  One of the many ailments that A-Bomb victims faced was Acute Radiation Syndrome.

      Due to residual radiation, Acute radiation syndrome is what many victims in Hiroshima received during the months following the bombing. A few hours after the explosion, vomiting was the first indication. Later, ones hair would fall out, or it will just become more thin and eventually break off which was a devastating loss for Japanese women, who valued their long black tresses more than anything (save their families). Vomiting, diarrhea, blood cells reduction, bleeding, hair loss, transitory infertility in males,  and lens opacity are the most common symptoms that resulted from ARS (acute radiation syndrome).  Other symptoms that victims experienced were accumulation of fluid in the brain, an increase in white blood cells, intestinal bleeding, impaired function of organs (such as the kidneys and lungs), anemia, fetal wastage (miscarriages), teratogenicity (birth defects), mental retardation, intrauterine growth retardation, and induction of cancers (such as leukemia).

The severity of the symptom, depended upon the dose of radiation one received. If the dose of radiation was small, then not all of these symptoms  occurred. If the dose of the radiation was over 7 joules (per kg), one could die of bone marrow disorder in two or more months. Any higher then the person would probably die  in ten to twenty days after exposure, most likely because of intestinal disorder.

Other types of radiation include neutron rays, alpha rays, beta rays, and gamma rays. Neutrons are what triggers a nuclear chain reaction to explode an Atomic bomb (they spilt the atom). However, neutrons do  hardly any damage to cells, but they do cause various kinds of damage to the human body.  All of the types of radiation, such as alpha rays,  (refer to terms to know) contrasts with the other forms of radiation, and all of them developed during or after the A-bombs hit Hiroshima and Nagasaki.  Fortunately both Hiroshima and Nagasaki are no longer radioactive; therefore, there is no longer a threat of ARS (at least in a large quantity in a population [only those through genetic ties]) or such mass quantities of death by radiation now, as well as in the future.

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