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Different types of electromagnetic radiation. Non-ionizing (or non-ionising) radiation refers to any type of electromagnetic radiation that does not carry enough energy per quantum (photon energy) to ionize atoms or molecules—that is, to completely remove an electron from an atom or molecule. [1]
In the United States, non-ionizing radiation is regulated in the Radiation Control for Health and Safety Act of 1968 and the Occupational Safety and Health Act of 1970. [55] In Canada, various federal acts govern non-ionizing radiation by originating source, such as the Radiation Emitting Devices Act, the Canada Consumer Product Safety Act, and ...
Planned exposure – limits given for occupational, medical and public exposure. The occupational exposure limit of effective dose is 20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv. The public exposure limit is 1 mSv in a year.
The effective dose is the risk of radiation averaged over the entire body. [4] Ionizing radiation is known to cause cancer in humans. [4] We know this from the Life Span Study, which followed survivors of the atomic bombing in Japan during World War 2. [5] [4] Over 100,000 individuals were followed for 50 years.
A year after Röntgen's discovery of X-rays in 1895, the American engineer Wolfram Fuchs gave what was probably the first radiation protection advice, but many early users of X-rays were initially unaware of the hazards and protection was rudimentary or non-existent. [11] The dangers of radioactivity and radiation were not immediately recognized.
Estimates suggest that less than 2Gy of radiation could destroy half of a female’s immature oocytes. Female ovaries are estimated to store over 1,000,000 primordial follicles at birth which decrease in number and quality with increasing age via processes such as apoptosis. [1] Radiation therapy greatly accelerates this decline.
The hazard from contamination is the emission of ionizing radiation. The principal radiations which will be encountered are alpha, beta and gamma, but these have quite different characteristics. They have widely differing penetrating powers and radiation effects, and the accompanying diagram shows the penetration of these radiations in simple ...
The depth of penetration depends on the frequency of the microwaves and the tissue type. The Active Denial System ("pain ray") is a less-lethal directed energy weapon that employs a microwave beam at 95 GHz; a two-second burst of the 95 GHz focused beam heats the skin to a temperature of 130 °F (54 °C) at a depth of 1/64th of an inch (0.4 mm) and is claimed to cause skin pain without lasting ...