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radioactivity

GC: n

CT: The scale of the nuclear disaster in Japan caused by the earthquake and tsunami in March 2011, in terms of releases from the nuclear power stations in Fukushima, was not as great as Chernobyl. Radioactive material released into the atmosphere is dispersed around the world, and indeed was detected here on the Isle of Man, but with only very low levels of radioactivity in the form of Iodine-131 found in our rainwater for a few days a fortnight after the disaster. Although it was not expected to give rise to sufficient fallout here to be of concern for human health or to have an adverse effect on water or food production, Government Laboratory staff ensured that they maintained awareness of events as they developed, and kept a close watch on our own environmental monitoring data, and that from neighbouring countries. The amount found in the rainwater was less than 1/100th of the lowest level considered to give cause for concern for human health, and nothing was detectable in milk.

S: https://www.gov.im/categories/the-environment-and-greener-living/isle-of-man-government-laboratory/environmental-radioactivity/(external link) (last access: 10 December 2015)

N: 1. In 1899, from French radioactivité, coined 1898 by the Curies. From radiation: mid-15c., "act or process of radiating," from Middle French radiation and directly from Latin radiationem (nominative radiatio) "a shining, radiation," noun of action from past participle stem of radiare "to beam, shine, gleam; make beaming," from radius "beam of light; spoke of a wheel".
2. Property exhibited by certain types of matter of emitting energy and subatomic particles spontaneously. It is, in essence, an attribute of individual atomic nuclei.
3. There are 3 different types of radiation:
- Alpha radiation: is a heavy, very short-range particle and is actually an ejected helium nucleus.
  • Most alpha radiation is not able to penetrate human skin.
  • Alpha-emitting materials can be harmful to humans if the materials are inhaled, swallowed, or absorbed through open wounds.
  • A variety of instruments has been designed to measure alpha radiation. Special training in the use of these instruments is essential for making accurate measurements.
  • A thin-window Geiger-Mueller (GM) probe can detect the presence of alpha radiation.
  • Instruments cannot detect alpha radiation through even a thin layer of water, dust, paper, or other material, because alpha radiation is not penetrating.
  • Alpha radiation travels only a short distance (a few inches) in air, but is not an external hazard.
  • Alpha radiation is not able to penetrate clothing.
  • Examples of some alpha emitters: radium, radon, uranium, thorium.
- Beta radiation: is a light, short-range particle and is actually an ejected electron.
  • Beta radiation may travel several feet in air and is moderately penetrating.
  • Beta radiation can penetrate human skin to the "germinal layer," where new skin cells are produced. If high levels of beta-emitting contaminants are allowed to remain on the skin for a prolonged period of time, they may cause skin injury.
  • Beta-emitting contaminants may be harmful if deposited internally.
  • Most beta emitters can be detected with a survey instrument and a thin-window GM probe (e.g., "pancake" type). Some beta emitters, however, produce very low-energy, poorly penetrating radiation that may be difficult or impossible to detect. Examples of these difficult-to-detect beta emitters are hydrogen-3 (tritium), carbon-14, and sulfur-35.
  • Clothing provides some protection against beta radiation.
  • Examples of some pure beta emitters: strontium-90, carbon-14, tritium, and sulfur-35.
- Gamma and X Radiation: Gamma radiation and x rays are highly penetrating electromagnetic radiation. Some characteristics of these radiations are:
  • Gamma radiation or x rays are able to travel many feet in air and many inches in human tissue. They readily penetrate most materials and are sometimes called "penetrating" radiation.
  • X rays are like gamma rays. X rays, too, are penetrating radiation. Sealed radioactive sources and machines that emit gamma radiation and x rays respectively constitute mainly an external hazard to humans.
  • Gamma radiation and x rays are electromagnetic radiation like visible light, radiowaves, and ultraviolet light. These electromagnetic radiations differ only in the amount of energy they have.
  • Gamma rays and x rays are the most energetic of these. Dense materials are needed for shielding from gamma radiation.
  • Clothing provides little shielding from penetrating radiation, but will prevent contamination of the skin by gamma-emitting radioactive materials.
  • Gamma radiation is easily detected by survey meters with a sodium iodide detector probe. Gamma radiation and/or characteristic x rays frequently accompany the emission of alpha and beta radiation during radioactive decay. Examples of some gamma emitters: iodine-131, cesium-137, cobalt-60, radium-226, and technetium-99m.
4. Cultural Interrelation: We can mention, among others, Collected Novels, Short Stories, Essays and Articles, by H. G. Wells (1866-1946).

S: 1. OED - http://www.etymonline.com/index.php?term=radiation&allowed_in_frame=0(external link) (last access: 11 December 2015). 2. EncBrit - http://global.britannica.com/science/radioactivity(external link) (last access: 11 December 2015). 3. HPS - http://hps.org/publicinformation/ate/faqs/radiationtypes.html(external link) (last access: 11 December 2015). 4. e-artnow 2015 - https://goo.gl/b9S7yl(external link) (last access: 11 December 2015).

SYN:
S:

CR: depleted uranium, gamma radiation, lepton (EN), linear accelerator, nuclear energy, quark (EN), radioactive contamination, radioactive decay, radioactive waste, radon (EN), synchrotron.



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