Irradiation

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Irradiation is the process by which an object is exposed to radiation. The exposure can originate from various sources, including natural sources. Most frequently the term refers to ionizing radiation, and to a level of radiation that will serve a specific purpose, rather than radiation exposure to normal levels of background radiation. The term irradiation usually excludes the exposure to non-ionizing radiation, such as infrared, visible light, microwaves from cellular phones or electromagnetic waves emitted by radio and TV receivers and power supplies.

Contents

Applications

Sterilization

If administered at appropriate levels, all forms of ionizing radiation can sterilize objects, including medical instruments, disposables such as syringes, and sterilize food. Ionizing radiation (electron beams, X-rays and gamma rays) [1] may be used to kill bacteria in food or other organic material, including blood.[ citation needed ] Food irradiation, while effective, is seldom used due to problems with public acceptance. [2]

Medicine

Irradiation is used in diagnostic imaging, cancer therapy and blood transfusion. [3]

In 2011 researchers found that irradiation was successful in the novel theranostic technique involving co-treatment with heptamethine dyes to elucidate tumor cells and attenuate their growth with minimal side effects. [4] [5]

Ion implantation

Ion irradiation is routinely used to implant impurities atoms into materials, especially semiconductors, to modify their properties. This process, usually known as ion implantation, is an important step in the manufacture of silicon integrated circuits.

Ion irradiation

Ion irradiation means in general using particle accelerators to shoot energetic ions on a material. Ion implantation is a variety of ion irradiation, as is swift heavy ions irradiation from particle accelerators induces ion tracks that can be used for nanotechnology.

Industrial chemistry

Irradiation can be used to cross-link plastics or to improve material qualities of semi-precious stones. Due to its efficiency, electron beam processing is often used in the irradiation treatment of polymer-based products to improve their mechanical, thermal, and chemical properties, and often to add unique properties. Cross-linked polyethylene pipe (PEX), high-temperature products such as tubing and gaskets, wire and cable jacket curing, curing of composite materials, and crosslinking of tires are a few examples.

Security

During the 2001 anthrax attacks, the US Postal Service irradiated mail to protect members of the US government and other possible targets. This was of some concern to people who send digital media through the mail, including artists. According to the ART in Embassies program, "incoming mail is irradiated, and the process destroys slides, transparencies and disks."[ citation needed ]

Agriculture

After its discovery by Lewis Stadler at the University of Missouri, irradiation of seed and plant germplasm has resulted in creating many widely-grown cultivars of food crops worldwide. [6] The process, which consists of striking plant seeds or germplasm with radiation in the form of X-rays, UV waves, heavy-ion beams, or gamma rays, essentially "mixes" the genes already existing in the genome. The UN has been an active participant through the International Atomic Energy Agency. Irradiation is also employed to prevent the sprouting of certain cereals, onions, potatoes and garlic. [7] Appropriate irradiation doses are also used to produce insects for use in the sterile insect technique of pest control. [8]

The U.S. Department of Agriculture's (USDA) Food Safety and Inspection Service (FSIS) recognizes irradiation as an important technology to protect consumers. Fresh meat and poultry including whole or cut up birds, skinless poultry, pork chops, roasts, stew meat, liver, hamburgers, ground meat, and ground poultry are approved for irradiation. [9]

Assassination

Some claim that Gheorghe Gheorghiu-Dej, who died of lung cancer in Bucharest on March 19, 1965, was intentionally irradiated during a visit to Moscow, due to his political stance. [10]

In 1999, an article in Der Spiegel alleged that the East German MfS intentionally irradiated political prisoners with high-dose radiation, possibly to provoke cancer. [11] [12]

Alexander Litvinenko, a secret serviceman who was tackling organized crime in Russia, was intentionally poisoned with Po-210; the very large internal doses of radiation he received caused his death.

Related Research Articles

Food irradiation Sterilization of food with ionizing radiations for enhanced preservation and longer shelflife

Food irradiation is the process of exposing food and food packaging to ionizing radiation. Ionizing radiation, such as from gamma rays, x-rays, or electron beams, is energy that can be transmitted without direct contact to the source of the energy (radiation) capable of freeing electrons from their atomic bonds (ionization) in the targeted food. The radiation can be emitted by a radioactive substance or generated electrically. This treatment is used to improve food safety by extending product shelf-life (preservation), reducing the risk of foodborne illness, delaying or eliminating sprouting or ripening, by sterilization of foods, and as a means of controlling insects and invasive pests. Food irradiation primarily extends the shelf-life of irradiated foods by effectively destroying organisms responsible for spoilage and foodborne illness and inhibiting sprouting.

Particle radiation is the radiation of energy by means of fast-moving subatomic particles. Particle radiation is referred to as a particle beam if the particles are all moving in the same direction, similar to a light beam.

Radiation Waves or particles propagating through space or through a medium, carrying energy

In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes:

Beta particle ionizing radiation

A beta particle, also called beta ray or beta radiation, is a high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic nucleus during the process of beta decay. There are two forms of beta decay, β decay and β+ decay, which produce electrons and positrons respectively.

Nuclear technology Technology that involves the reactions of atomic nuclei

Nuclear technology is technology that involves the nuclear reactions of atomic nuclei. Among the notable nuclear technologies are nuclear reactors, nuclear medicine and nuclear weapons. It is also used, among other things, in smoke detectors and gun sights.

Acute radiation syndrome health problems caused by exposure to very high levels of ionizing radiation

Acute radiation syndrome (ARS), also known as radiation sickness or radiation poisoning, is a collection of health effects due to exposure to high amounts of ionizing radiation over a short period of time. Within the first days symptoms may include nausea, vomiting, and loss of appetite. This may then be followed by a few hours or weeks with little symptoms. After this, depending on the total dose of radiation, people may develop infections, bleeding, dehydration, and confusion, or there may be a period with few symptoms. This is finally followed by either recovery or death. The symptoms can begin within one hour and may last for several months.

Ionizing radiation Radiation that carries enough light energy to liberate electrons from atoms or molecules

Ionizing radiation is radiation that carries sufficient energy to detach electrons from atoms or molecules, thereby ionizing them. Ionizing radiation is made up of energetic subatomic particles, ions or atoms moving at high speeds, and electromagnetic waves on the high-energy end of the electromagnetic spectrum.

The gray is a derived unit of ionizing radiation dose in the International System of Units (SI). It is defined as the absorption of one joule of radiation energy per kilogram of matter.

Radiation protection, also known as radiological protection, is defined by the International Atomic Energy Agency (IAEA) as "The protection of people from harmful effects of exposure to ionizing radiation, and the means for achieving this". Exposure can be from a source of radiation external to the human body or due to internal irradiation caused by the ingestion of radioactive contamination.

Sterilization refers to any process that eliminates, removes, kills, or deactivates all forms of life and other biological agents like prions present in a specific surface, object or fluid, for example food or biological culture media. Sterilization can be achieved through various means, including heat, chemicals, irradiation, high pressure, and filtration. Sterilization is distinct from disinfection, sanitization, and pasteurization, in that those methods reduce rather than eliminate all forms of life and biological agents present. After sterilization, an object is referred to as being sterile or aseptic.

Kerma is an acronym for "kinetic energy released per unit mass", defined as the sum of the initial kinetic energies of all the charged particles liberated by uncharged ionizing radiation in a sample of matter, divided by the mass of the sample. It is defined by the quotient .

Cobalt-60 isotope of cobalt

Cobalt-60 (60Co), is a synthetic radioactive isotope of cobalt with a half-life of 5.2713 years. It is produced artificially in nuclear reactors. Deliberate industrial production depends on neutron activation of bulk samples of the monoisotopic and mononuclidic cobalt isotope 59
Co
. Measurable quantities are also produced as a by-product of typical nuclear power plant operation and may be detected externally when leaks occur. In the latter case the incidentally produced 60
Co
is largely the result of multiple stages of neutron activation of iron isotopes in the reactor's steel structures via the creation of 59
Co
precursor. The simplest case of the latter would result from the activation of 58
Fe
. 60
Co
decays by beta decay to the stable isotope nickel-60. The activated nickel nucleus emits two gamma rays with energies of 1.17 and 1.33 MeV, hence the overall nuclear equation of the reaction is 59
27
Co
+ n → 60
27
Co
60
28
Ni
+ e +
ν
e
+ gamma rays.

The National Oncologic Institute or ION is a specialized hospital for cancer treatment, located in Panama City, Panama. Between August 2000 and March 2001, patients receiving radiation treatment for prostate cancer and cancer of the cervix received lethal doses of radiation, resulting in eight fatalities.

Radiobiology is a field of clinical and basic medical sciences that involves the study of the action of ionizing radiation on living things, especially health effects of radiation. Ionizing radiation is generally harmful and potentially lethal to living things but can have health benefits in radiation therapy for the treatment of cancer and thyrotoxicosis. Its most common impact is the induction of cancer with a latent period of years or decades after exposure. High doses can cause visually dramatic radiation burns, and/or rapid fatality through acute radiation syndrome. Controlled doses are used for medical imaging and radiotherapy.

Electron-beam processing or electron irradiation (EBI) is a process that involves using electrons, usually of high energy, to treat an object for a variety of purposes. This may take place under elevated temperatures and nitrogen atmosphere. Possible uses for electron irradiation include sterilization and cross-linking of polymers.

Gamma ray Energetic electromagnetic radiation arising from radioactive decay of atomic nuclei

A gamma ray, or gamma radiation, is a penetrating electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves and so imparts the highest photon energy. Paul Villard, a French chemist and physicist, discovered gamma radiation in 1900 while studying radiation emitted by radium. In 1903, Ernest Rutherford named this radiation gamma rays based on their relatively strong penetration of matter; in 1900 he had already named two less penetrating types of decay radiation alpha rays and beta rays in ascending order of penetrating power.

Ari Brynjolfsson was an Icelandic physicist known for his work in America on food irradiation and for the development of radiation facilities.

Radioactive source

A radioactive source is a known quantity of a radionuclide which emits ionizing radiation; typically one or more of the radiation types gamma rays, alpha particles, beta particles, and neutron radiation.

Philippine Nuclear Research Institute Agency of the Philippine government

The Philippine Nuclear Research Institute (PNRI) is a government agency under the Department of Science and Technology mandated to undertake research and development activities in the peaceful uses of nuclear energy, institute regulations on the said uses, and carry out the enforcement of said regulations to protect the health and safety of radiation workers and the general public.

Phytosanitary irradiation is a treatment that uses ionizing radiation on commodities, such as fruits and vegetables to inactivate pests, such as insects. This method is used for international food trade as a means to prevent spread of non-native organisms. It is used as an alternative to conventional techniques, which includes heat treatment, cold treatment, pesticide sprays, high pressure treatment, cleaning, waxing or chemical fumigation. It is often used on spices, grains, and non-food items. It inhibits the species reproduction cycle by destroying nuclear material primarily, whereas other methods are measured by species mortality. Each country has different effective approved dosages, although most follow guidelines established by the IPPC which has issued guidelines referred to as the International Standards for Phytosanitary Measures (ISPM). The most commonly used dose is 400 Gy based on USDA-APHIS guidelines.

References

  1. "Food Standards Agency - Irradiated food" . Retrieved 2008-01-26.
  2. "Spinach and Peanuts, With a Dash of Radiation" article by Andrew Marin in The New York Times February 1, 2009
  3. "Information for patients needing irradiated blood" by National Blood Service
  4. Tan X, Luo S, Wang D, et al. A NIR heptamethine Dye with intrinsic cancer targeting, imaging and photosynthesizing properties. Journal of Biomaterials China. 33-7 (2011), pp. 2230-2239.
  5. F. Pene, E. Courtine, A. Cariou, J.P. Mira. Toward theranostics. Crit Care Med, 37 (2009), pp. S50–S58
  6. Ahloowalia, B.S.; Maluszynski, M.; Nichterlein, K. (2004). "Global impact of mutation-derived varieties". Euphytica. 135 (2): 187–204. doi:10.1023/B:EUPH.0000014914.85465.4f.
  7. Bly, J.H. "Electron Beam Processing", Yardley, PA: International Information Associates, 1988.
  8. International Database on Insect Disinfestation and Sterilization, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture website, Food and Agriculture Organization of the United Nations, plus the International Atomic Energy Agency.
  9. Irradiation and Food Safety, U.S. Drug and Food Administration. Retrieved Jan. 5, 2010.
  10. "TFP > Alexander Litvinenko Assassination". Archived from the original on 2011-07-01. Retrieved 2009-10-18.
  11. STASI: In Kopfhöhe ausgerichtet. Article by Peter Wensierski in Der Spiegel 20/1999, May 17, 1999
  12. Tödliche Strahlung. Die Staatssicherheit der DDR steht im Verdacht, Regimegegner radioaktiv verseucht zu haben. Article by Paul Leonhard in Junge Freiheit April 14, 2000

See also