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Irradiation

Irradiation

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Irradiation is the process by which an object is exposed to radiation
Radiation
In physics, radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiation; ionizing and non-ionizing...

. The exposure can originate from various sources, including natural sources. Most frequently the term refers to ionizing radiation
Ionizing radiation
Ionizing radiation is radiation composed of particles that individually have sufficient energy to remove an electron from an atom or molecule. This ionization produces free radicals, which are atoms or molecules containing unpaired electrons...

, and to a level of radiation that will serve a specific purpose, rather than radiation
Radiation
In physics, radiation is a process in which energetic particles or energetic waves travel through a medium or space. There are two distinct types of radiation; ionizing and non-ionizing...

 exposure to normal levels of background radiation
Background radiation
Background radiation is the ionizing radiation constantly present in the natural environment of the Earth, which is emitted by natural and artificial sources.-Overview:Both Natural and human-made background radiation varies by location....

. The term irradiation usually excludes the exposure to non-ionizing radiation, such as microwaves from cellular phones or electromagnetic waves emitted by radio and TV receivers and power supplies.

Sterilization


If administered at appropriate levels, all of these forms of radiation can be used to sterilize
Sterilization (microbiology)
Sterilization is a term referring to any process that eliminates or kills all forms of microbial life, including transmissible agents present on a surface, contained in a fluid, in medication, or in a compound such as biological culture media...

 objects, a technique used in the production of medical instruments and disposables, such as syringe
Syringe
A syringe is a simple pump consisting of a plunger that fits tightly in a tube. The plunger can be pulled and pushed along inside a cylindrical tube , allowing the syringe to take in and expel a liquid or gas through an orifice at the open end of the tube...

s as well as in the disinfestation and sterilization of food
Food irradiation
Food irradiation is the process of exposing food to ionizing radiation to destroy microorganisms, bacteria, viruses, or insects that might be present in the food. Further applications include sprout inhibition, delay of ripening, increase of juice yield, and improvement of re-hydration...

. Small doses of ionizing radiation (electron beam processing
Electron beam processing
Electron beam processing or electron irradiation is a process which 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...

, X-rays and gamma rays) may be used to kill bacteria in food, or other organic material, including blood. Irradiation also includes (by the principle) microwave heating. Food irradiation
Food irradiation
Food irradiation is the process of exposing food to ionizing radiation to destroy microorganisms, bacteria, viruses, or insects that might be present in the food. Further applications include sprout inhibition, delay of ripening, increase of juice yield, and improvement of re-hydration...

, while effective, is seldom used due to public relations problems.

Medicine


It is also used in Diagnostic Imaging, cancer therapy
Radiation therapy
Radiation therapy , radiation oncology, or radiotherapy , sometimes abbreviated to XRT or DXT, is the medical use of ionizing radiation, generally as part of cancer treatment to control malignant cells.Radiation therapy is commonly applied to the cancerous tumor because of its ability to control...

 and blood transfusion
Blood transfusion
Blood transfusion is the process of receiving blood products into one's circulation intravenously. Transfusions are used in a variety of medical conditions to replace lost components of the blood...

.

Ion implantation


Ion irradiation is routinely used to implant impurity atom
Atom
The atom is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. The atomic nucleus contains a mix of positively charged protons and electrically neutral neutrons...

s into materials, especially
semiconductor
Semiconductor
A semiconductor is a material with electrical conductivity due to electron flow intermediate in magnitude between that of a conductor and an insulator. This means a conductivity roughly in the range of 103 to 10−8 siemens per centimeter...

s, to modify their properties. This process, usually known
as ion implantation
Ion implantation
Ion implantation is a materials engineering process by which ions of a material are accelerated in an electrical field and impacted into another solid. This process is used to change the physical, chemical, or electrical properties of the solid...

, is a very important step in the manufacturing of silicon
integrated circuit
Integrated circuit
An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...

s.

Ion irradiation


The irradiation of solids by swift heavy ions from particle accelerators induces ion tracks which can be used for nanotechnology
Nanotechnology
Nanotechnology is the study of manipulating matter on an atomic and molecular scale. Generally, nanotechnology deals with developing materials, devices, or other structures possessing at least one dimension sized from 1 to 100 nanometres...

.

Industrial chemistry


Irradiation can furthermore be used in cross-linking of plastics or to improve material qualities of semi-precious stones. Due to its efficiency, electron beam processing
Electron beam processing
Electron beam processing or electron irradiation is a process which 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...

 is often used in the irradiation treatment of polymer-based products to improve the mechanical, thermal, and chemical properties, and often adding 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
2001 anthrax attacks
The 2001 anthrax attacks in the United States, also known as Amerithrax from its Federal Bureau of Investigation case name, occurred over the course of several weeks beginning on Tuesday, September 18, 2001, one week after the September 11 attacks. Letters containing anthrax spores were mailed to...

, the US Postal Service irradiated mail
Irradiated mail
Irradiated mail is mail that has been deliberately exposed to radiation, typically in an effort to disinfect it. The most notable instance of mail irradiation occurred in response to the 2001 anthrax attacks; the level of radiation chosen to kill anthrax spores was so high that it often changed the...

 to protect members of the US government and other possible targets. This can be of some concern to people, including artists; according to the ART in Embassies program "incoming mail is irradiated, and the process destroys slides, transparencies and disks."http://aiep.state.gov/submit.html

Agriculture


After its discovery by Lewis Stadler at the University of Missouri
University of Missouri
The University of Missouri System is a state university system providing centralized administration for four universities, a health care system, an extension program, five research and technology parks, and a publishing press. More than 64,000 students are currently enrolled at its four campuses...

, irradiation of seed
Seed
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth within the mother plant...

 and plant germplasm
Germplasm
A germplasm is a collection of genetic resources for an organism. For plants, the germplasm may be stored as a seed collection or, for trees, in a nursery.-See also:*Germ plasm, the germ cell determining zone...

 has resulted in creating many of the most widely grown strains of food crops worldwide. The process, which consists of striking plant seeds or germplasm by radiation in the form of X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...

s, UV waves, heavy-ion beams
Ion beam
An ion beam is a type of charged particle beam consisting of ions. Ion beams have many uses in electronics manufacturing and other industries. A variety of ion beam sources exist, some derived from the mercury vapor thrusters developed by NASA in the 1960s.-Ion beam etching or sputtering:One type...

, gamma ray
Gamma ray
Gamma radiation, also known as gamma rays or hyphenated as gamma-rays and denoted as γ, is electromagnetic radiation of high frequency . Gamma rays are usually naturally produced on Earth by decay of high energy states in atomic nuclei...

s, essentially "mixes" the genes already existing in genome
Genome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....

. The UN has been active in this through the International Atomic Energy Agency
International Atomic Energy Agency
The International Atomic Energy Agency is an international organization that seeks to promote the peaceful use of nuclear energy, and to inhibit its use for any military purpose, including nuclear weapons. The IAEA was established as an autonomous organization on 29 July 1957...

. Irradiation is also employed to prevent sprouting of certain cereal
Cereal
Cereals are grasses cultivated for the edible components of their grain , composed of the endosperm, germ, and bran...

s, onion
Onion
The onion , also known as the bulb onion, common onion and garden onion, is the most widely cultivated species of the genus Allium. The genus Allium also contains a number of other species variously referred to as onions and cultivated for food, such as the Japanese bunching onion The onion...

s, potatoes and garlic
Garlic
Allium sativum, commonly known as garlic, is a species in the onion genus, Allium. Its close relatives include the onion, shallot, leek, chive, and rakkyo. Dating back over 6,000 years, garlic is native to central Asia, and has long been a staple in the Mediterranean region, as well as a frequent...

. Appropriate irradiation doses are also used to produce sterile insects to be used in the sterile insect technique
Sterile insect technique
The sterile insect technique is a method of biological control, whereby overwhelming numbers of sterile insects are released. The released insects are normally male as it is the female that causes the damage, usually by laying eggs in the crop, or, in the case of mosquitoes, taking a bloodmeal from...

.
The U.S. Department of Agriculture's (USDA) Food Safety and Inspection Service (FSIS) recognizes irradiation as an important technology to protecting consumers
Food safety
Food safety is a scientific discipline describing handling, preparation, and storage of food in ways that prevent foodborne illness. This includes a number of routines that should be followed to avoid potentially severe health hazards....

. Fresh meat
Meat
Meat is animal flesh that is used as food. Most often, this means the skeletal muscle and associated fat and other tissues, but it may also describe other edible tissues such as organs and offal...

 and poultry
Poultry
Poultry are domesticated birds kept by humans for the purpose of producing eggs, meat, and/or feathers. These most typically are members of the superorder Galloanserae , especially the order Galliformes and the family Anatidae , commonly known as "waterfowl"...

 including whole or cut up birds, skinless poultry, pork chop
Pork chop
A pork chop is a cut of pork cut perpendicularly to the spine of the pig and usually containing a rib or part of a vertebra, served as an individual portion.-Variations:...

s, roasts, stew meat, liver, hamburger
Hamburger
A hamburger is a sandwich consisting of a cooked patty of ground meat usually placed inside a sliced bread roll...

s, ground meat
Ground meat
Ground meat is meat finely chopped by a meat grinder or a chopping knife. It is called minced meat or more usually mince outside North America....

, and ground poultry are approved for irradiation.

Assassination


Gheorghe Gheorghiu-Dej
Gheorghe Gheorghiu-Dej
Gheorghe Gheorghiu-Dej was the Communist leader of Romania from 1948 until his death in 1965.-Early life:Gheorghe was the son of a poor worker, Tănase Gheorghiu, and his wife Ana. Gheorghiu-Dej joined the Communist Party of Romania in 1930...

 died of lung cancer in Bucharest on March 19, 1965. Some claim that he was intentionally irradiated during a visit to Moscow, due to his political stance.

In 1999, an article in Der Spiegel
Der Spiegel
Der Spiegel is a German weekly news magazine published in Hamburg. It is one of Europe's largest publications of its kind, with a weekly circulation of more than one million.-Overview:...

 alleged that the East German MfS
Stasi
The Ministry for State Security The Ministry for State Security The Ministry for State Security (German: Ministerium für Staatssicherheit (MfS), commonly known as the Stasi (abbreviation , literally State Security), was the official state security service of East Germany. The MfS was headquartered...

intentionally irradiated political prisoners with high-dose radiation, possibly to provoke cancer in them.

Alexander Litvinenko was intentionally poisoned with Po-210 which subsequently killed with the very large internal doses of radiation he was receiving.

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