Ionizing radiation artificial

Isotopes are atoms of the same elements having different mass numbers. Radioisotopes are the isotopes of an element that are radioactive or emit ionizing radiation. All elements are known to form artificial radioactive isotopes by nuclear bombardment. 

In order to understand the role of flavonoids in pollen, flavonoid-deficient mutants have been produced through artificial methods, such as cosuppression, antisense expression, chemical mutagenesis, and ionizing radiation. Examples include and A. thali-... 

Stress and exposure to electromagnetic radiation (UV or ionizing radiation) are immunosuppressant. People who bask under artificial UV sun lamps have been found to have suppressed immune responses, as have bereaved individuals. It is known, for example, that the combined effect of exposure to ionizing radiation and physical trauma (burns or wounds) produces a synergistic immunosuppressant effect. 

Sources of Ionizing Radiation We are continuously exposed to ionizing radiation from natural and artificial sources (Table 23.6, next page). Indeed, life evolved in the presence of natural ionizing radiation, called background radiation. The same radiation that can alter bonds in DNA and cause harmful mutations also causes beneficial mutations that, over time, allow organisms to adapt and species to change. 

Measurements of ionizing radiation and radionuclides in foods and environmental samples are required for the assessment of exposure to both natural and artificial radiation sources, determination of compliance with government regulations, and studies of the movement and retention of artificial radionuclides in food and environmental media and of the composition of the natural radiation enviromnent. 

Natural Radiation There are two main sources of ionizing radiation natural and artificial. Natural radiation sources include cosmic and gamma radiation found in certain sods. Building products made from these radioactive soils also give off natural radiation. Natural radiation is also present in some ingested food and water and some inhaled air. Natural exposures vary considerably by geographic location. 

Artificial Radiation Artificial sources that expose the general population include certain consumer products, medical procedures, occupational sources, and general environment sources. Products with ionizing radiation include analog television sets and computer monitors, some smoke detectors, luminous dials on clocks, and luminous signs. Medical sources are gamma, beta, and X-rays for diagnostic and treatment procedures. Occupational sources involve jobs related to... 

Ionizing radiation in the environment arises firom both natural and artificial sources. Natural sources include cosmic rays and y-rays from Earth artificial sources include X-rays in medicine and discharges of radioactive waste from the nuclear industry. Sometimes the separation between natural and artificial sources involves difficulties for example, the radionuclides and in the air can result firom both cosmic rays and the nuclear industry. 

Ionizing radiation and radioactive substances are natural and permanent features of life on the Earth, and thus the risks associated with the radiation can only be restricted, not eliminated. Additionally, sources of ionizing radiation become essential to human practice in energy supplying, in modem health care including X-ray diagnostics and radiation therapy, etc. The use of artificial radiation is widespread. 

The main objective of the current system of radiation protection is to provide humans with adequate protection from the unacceptable effects of ionizing radiation therefore, it requires the assessment of pathways leading to their exposure. A certain level of contamination in the environment will imply a certain dose in humans. Envirorunental radiation protection therefore deals with those pathways that originate from envirorunental media and edible biota in areas liable to contamination by artificial radionucKdes (or enhanced levels of natural radioactive materials). 

Medical applications of ionizing radiation are the largest artificial sources of radiation exposure, and population exposures from the diagnostic and therapeutic uses of ionizing radiation... 

What is ionizing radiation, and why is it hazardous Ionizing radiation is produced by various physical mechanisms some radiations are the result of natural processes and others can be created by artificial means. Some sources of radiation are from natural radioactivity, from x-rays, from artificial sources or processes, and fi om cosmic rays which originate in space (see Section 13.5). 

Neutrons, the fourth major type of ionizing radiation, are rarely used in biomedical laboratories. Sources of neutrons are spontaneously fissioning isotopes (e.g., some of the artificial transuranic elements), atomic reactors, accelerators, and from reactions involving the interaction of alpha or gamma radiation on beryllium or certain other elements. Since the study of neutron radiation charac-... 

Equivalent dose (ED) Dose of ionizing radiation received by a sample subsequent to the event being dated, as evaluated from measurements of natural and artificial luminescence. ED can also be denoted by the term De. An alternative term is palaeodose (P). 

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