Irradiation is the process by which an object is exposed to

radiation 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: * ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visi ...

. The exposure can originate from various sources, including natural sources. Most frequently the term refers to

ionizing radiation Ionizing radiation (or ionising radiation), including nuclear radiation, consists of subatomic particles or electromagnetic waves that have sufficient energy to ionize atoms or molecules by detaching electrons from them. Some particles can travel ...

, and to a level of radiation that will serve a specific purpose, rather than radiation exposure to normal levels of

background radiation Background radiation is a measure of the level of ionizing radiation present in the environment at a particular location which is not due to deliberate introduction of radiation sources. Background radiation originates from a variety of source ...

. The term irradiation usually excludes the exposure to non-ionizing radiation, such as

infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of Light, visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from ...

visible light Light or visible light is electromagnetic radiation that can be perceived by the human eye. Visible light is usually defined as having wavelengths in the range of 400–700 nanometres (nm), corresponding to frequencies of 750–420 t ...

microwave Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency ra ...

s from cellular phones or

electromagnetic wave In physics, electromagnetic radiation (EMR) consists of waves of the electromagnetic (EM) field, which propagate through space and carry momentum and electromagnetic radiant energy. It includes radio waves, microwaves, infrared, (visible) ...

s emitted by radio and TV receivers and power supplies.

Applications

Sterilization

If administered at appropriate levels, all forms of

can sterilize objects, including medical instruments, disposables such as

syringe A syringe is a simple reciprocating pump consisting of a plunger (though in modern syringes, it is actually a piston) that fits tightly within a cylindrical tube called a barrel. The plunger can be linearly pulled and pushed along the inside ...

s, and sterilize food. Ionizing radiation ( electron beams,

X-rays An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nbs ...

and

gamma rays A gamma ray, also known as gamma radiation (symbol γ or \gamma), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves, typically ...

) may be used to kill bacteria in food or other organic material, including blood.

Food irradiation Food irradiation is the process of exposing food and food packaging to ionizing radiation, such as from gamma rays, x-rays, or electron beams. Food irradiation improves food safety and extends product shelf life (preservation) by effective ...

, while effective, is seldom used due to problems with public acceptance.

Medicine

Irradiation is used in diagnostic imaging,

cancer therapy Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...

and

blood transfusion Blood transfusion is the process of transferring blood products into a person's circulation intravenously. Transfusions are used for various medical conditions to replace lost components of the blood. Early transfusions used whole blood, but mo ...

. In 2011 researchers found that irradiation was successful in the novel

theranostic Personalized medicine, also referred to as precision medicine, is a medical model that separates people into different groups—with medical decisions, practices, interventions and/or products being tailored to the individual patient based on thei ...

technique involving co-treatment with heptamethine dyes to elucidate tumor cells and attenuate their growth with minimal side effects.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.F. Pene, E. Courtine, A. Cariou, J.P. Mira. Toward theranostics. Crit Care Med, 37 (2009), pp. S50–S58

Ion implantation

Ion irradiation is routinely used to implant impurities

atom Every atom is composed of a nucleus and one or more electrons bound to the nucleus. The nucleus is made of one or more protons and a number of neutrons. Only the most common variety of hydrogen has no neutrons. Every solid, liquid, gas, a ...

s into materials, especially

semiconductor A semiconductor is a material which has an electrical conductivity value falling between that of a conductor, such as copper, and an insulator, such as glass. Its resistivity falls as its temperature rises; metals behave in the opposite way ...

s, to modify their properties. This process, usually known as ion implantation, is an important step in the manufacture of silicon

integrated circuit An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, usually silicon. Large numbers of tiny ...

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 Nanotechnology, also shortened to nanotech, is the use of matter on an atomic, molecular, and supramolecular scale for industrial purposes. The earliest, widespread description of nanotechnology referred to the particular technological goal ...

Industrial chemistry

Irradiation can be used to cross-link

plastics Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into solid objects of various shapes. This adaptabi ...

or to improve material qualities of semi-precious stones as it is widely practised in jewelry industry. 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 2001 anthrax attacks, also known as Amerithrax (a portmanteau of "America" and "anthrax", from its FBI case name), occurred in the United States over the course of several weeks beginning on September 18, 2001, one week after the September 11 ...

, 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."

Agriculture

After its discovery by Lewis Stadler at the

University of Missouri The University of Missouri (Mizzou, MU, or Missouri) is a public land-grant research university in Columbia, Missouri. It is Missouri's largest university and the flagship of the four-campus University of Missouri System. MU was founded in ...

, irradiation of

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiosper ...

and plant germplasm has resulted in creating many widely-grown

cultivars A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture, ...

food crop A crop is a plant that can be grown and harvested extensively for profit or subsistence. When the plants of the same kind are cultivated at one place on a large scale, it is called a crop. Most crops are cultivated in agriculture or hydropon ...

s worldwide. The process, which consists of striking plant seeds or germplasm with radiation in the form of

X-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...

s, UV waves, heavy-ion beams, or

gamma ray A gamma ray, also known as gamma radiation (symbol γ or \gamma), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. It consists of the shortest wavelength electromagnetic waves, typically ...

s, essentially induce lesions of the DNA, leading to mutations in the

genome In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ...

. The UN has been an active participant through the

International Atomic Energy Agency The International Atomic Energy Agency (IAEA) is an intergovernmental organization that seeks to promote the peaceful use of nuclear energy and to inhibit its use for any military purpose, including nuclear weapons. It was established in 195 ...

. Irradiation is also employed to prevent the sprouting of certain

cereal A cereal is any grass cultivated for the edible components of its grain (botanically, a type of fruit called a caryopsis), composed of the endosperm, germ, and bran. Cereal grain crops are grown in greater quantities and provide more food ...

onion An onion (''Allium cepa'' L., from Latin ''cepa'' meaning "onion"), also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus '' Allium''. The shallot is a botanical variety of the on ...

potato The potato is a starchy food, a tuber of the plant ''Solanum tuberosum'' and is a root vegetable native to the Americas. The plant is a perennial in the nightshade family Solanaceae. Wild potato species can be found from the southern Uni ...

es and

garlic Garlic (''Allium sativum'') is a species of bulbous flowering plant in the genus '' Allium''. Its close relatives include the onion, shallot, leek, chive, Welsh onion and Chinese onion. It is native to South Asia, Central Asia and northeas ...

. Appropriate irradiation doses are also used to produce insects for use in the sterile insect technique of pest control. 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 Meat is animal flesh that is eaten as food. Humans have hunted, farmed, and scavenged animals for meat since prehistoric times. The establishment of settlements in the Neolithic Revolution allowed the domestication of animals such as chic ...

and

poultry Poultry () are domesticated birds kept by humans for their eggs, their meat or their feathers. These birds are most typically members of the superorder Galloanserae (fowl), especially the order Galliformes (which includes chickens, qu ...

including whole or cut up birds, skinless poultry, pork chops,

roast Roasting is a cooking method that uses dry heat where hot air covers the food, cooking it evenly on all sides with temperatures of at least from an open flame, oven, or other heat source. Roasting can enhance the flavor through caramelizatio ...

s, stew meat, liver,

hamburger A hamburger, or simply burger, is a food consisting of fillings—usually a patty of ground meat, typically beef—placed inside a sliced bun or bread roll. Hamburgers are often served with cheese, lettuce, tomato, onion, pickles, bacon, ...

ground meat Ground meat, called mince or minced meat outside North America, is meat finely chopped by a meat grinder or a chopping knife. A common type of ground meat is ground beef, but many other types of meats are prepared in a similar fashion, includ ...

, and ground poultry are approved for irradiation.

Assassination

Some claim that

Gheorghe Gheorghiu-Dej Gheorghe Gheorghiu-Dej (; 8 November 1901 – 19 March 1965) was a Romanian communist politician and electrician. He was the first Communist leader of Romania from 1947 to 1965, serving as first secretary of the Romanian Communist Part ...

, who died of lung cancer in Bucharest on March 19, 1965, was intentionally irradiated during a visit to Moscow, due to his political stance. In 1999, an article in ''

Der Spiegel ''Der Spiegel'' (, lit. ''"The Mirror"'') is a German weekly news magazine published in Hamburg. With a weekly circulation of 695,100 copies, it was the largest such publication in Europe in 2011. It was founded in 1947 by John Seymour Chaloner ...

'' alleged that the East German MfS intentionally irradiated political prisoners with high-dose radiation, possibly to provoke cancer.''Tödliche Strahlung. Die Staatssicherheit der DDR steht im Verdacht, Regimegegner radioaktiv verseucht zu haben.''
Article by Paul Leonhard in ''Junge Freiheit'' April 14, 2000

Alexander Litvinenko Alexander Valterovich "Sasha" Litvinenko (30 August 1962 ( at WebCite) or 4 December 1962 – 23 November 2006) was a British-naturalised Russian defector and former officer of the Russian Federal Security Service (FSB) who specialised i ...

, a secret serviceman who was tackling organized crime in Russia, was intentionally poisoned with

polonium-210 Polonium-210 (210Po, Po-210, historically radium F) is an isotope of polonium. It undergoes alpha decay to stable 206Pb with a half-life of 138.376 days (about months), the longest half-life of all naturally occurring polonium isotopes. First ...

; the very large internal doses of radiation he received caused his death.

References

{{reflist

External links

Industrial, Medical & Educational Uses of Radiation

Radiation Protection- US EPA

International Atomic Energy Agency (IAEA)

North American Seed Bank (NASB)