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Alpha particles, also called alpha rays or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. [5] They are generally produced in the process of alpha decay but may also be produced in other ways. Alpha particles are named after the first letter in the Greek alphabet, α.
Alpha radiation is a nuclear phenomenon in which a heavy radionuclide emits an energetic alpha particle (consisting of two protons and two neutrons) and transmutes to a different radionuclide. The emitted alpha particle has a range in tissue of only 40-90 microns, which minimizes collateral damage when used for treatment purposes.
The committed dose is not intended as a measure for deterministic effects, such as radiation sickness, which are defined as the severity of a health effect which is certain to happen. The radiation risk proposed by the International Commission on Radiological Protection (ICRP) predicts that an effective dose of one sievert carries a 5.5% chance ...
The effects of radiation on genes, including the effect of cancer risk, were recognized much later. In 1927, Hermann Joseph Muller published research showing genetic effects and, in 1946, was awarded the Nobel Prize in Physiology or Medicine for his findings.
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.
Beta particle (β) emitters such as yttrium-90 can travel considerable distances beyond the immediate tissue before depositing their energy, while alpha particles deposit their energy in 70–100 μm long tracks. [6] Alpha particles are more likely than other types of radiation to cause double-strand breaks to DNA molecules, which is one of ...
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Natural background radiation comes from five primary sources: cosmic radiation, solar radiation, external terrestrial sources, radiation in the human body, and radon. The background rate for natural radiation varies considerably with location, being as low as 1.5 mSv/a (1.5 mSv per year) in some areas and over 100 mSv/a in others.