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Surface contamination may either be fixed or "free". In the case of fixed contamination, the radioactive material cannot by definition be spread, but its radiation is still measurable. In the case of free contamination, there is the hazard of contamination spread to other surfaces such as skin or clothing, or entrainment in the air.
The additional radioactivity in the biosphere caused by human activity due to the releases of man-made radioactivity and of Naturally Occurring Radioactive Materials (NORM) can be divided into several classes. Normal licensed releases which occur during the regular operation of a plant or process handling man-made radioactive materials.
The international Radura logo, used to show a food has been treated with ionizing radiation. A portable, trailer-mounted food irradiation machine, c. 1968 Food irradiation (sometimes American English: radurization; British English: radurisation) is the process of exposing food and food packaging to ionizing radiation, such as from gamma rays, x-rays, or electron beams.
Joseph G. Hamilton was the primary researcher for the human plutonium experiments done at U.C. San Francisco from 1944 to 1947. [1] Hamilton wrote a memo in 1950 discouraging further human experiments because the AEC would be left open "to considerable criticism," since the experiments as proposed had "a little of the Buchenwald touch." [2]
Radon gas is a radioactive chemical element that is the largest source of background radiation, about 2mSv per year. [17] This is similar to a head CT (see table). Other sources include cosmic radiation, dissolved uranium and thorium in water, and internal radiation (humans have radioactive potassium-40 and carbon-14 inside their bodies from ...
The source of caesium was found to be rice straw that had been fed to the animals. A notice from the Japanese government that was sent to cattle farmers after the nuclear accident made no mention of the possibility that rice straw could be contaminated with radioactive materials from the fallout. [248]
Radioactive contamination is a potential danger for living organisms and results in external hazards, concerning radiation sources outside the body, and internal dangers, as a result of the incorporation of radionuclides inside the body (often by inhalation of particles or ingestion of contaminated food). [14] In humans, single doses from 0.25 ...
Research in this area has focused on the three most common sources of radiation used for these applications, including gamma, electron beam, and x-ray radiation. [ 17 ] The mechanisms of radiation damage are different for polymers and metals, since dislocations and grain boundaries do not have real significance in a polymer.