Ionizing radiation
Ionizing radiation is a type of energy released during the disintegration of unstable atomic nuclei, commonly associated with X and gamma radiation. This radiation can originate from both natural sources, like radon, and artificial sources, including nuclear reactors and medical diagnostic equipment. Exposure routes include inhalation, ingestion, and direct external contact. It poses health risks, notably an increased chance of developing various cancers such as lung, breast, and skin cancer, as well as leukemia. The mechanism of harm involves damage to DNA, potentially leading to cell mutations and malignancies over time. Furthermore, while ionizing radiation can be harmful, it is also utilized in medical treatments to target and destroy cancer cells, capitalizing on their vulnerability due to rapid division. Symptoms of exposure can vary from immediate reactions, such as nausea and confusion, to severe conditions like acute radiation syndrome following high doses. Historical advancements in the understanding of ionizing radiation have resulted in regulatory measures to protect public health, illustrating both the potential dangers and benefits associated with this form of energy.
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Ionizing radiation
ROC STATUS: Known human carcinogens include X radiation and gamma radiation (since 2004), neutrons (since 2004), radon (since 1994), and thorium dioxide (since 1981)
ALSO KNOWN AS: Gamma radiation, X radiation
RELATED CANCERS: Lung, bone, bone marrow (leukemia), thyroid, breast, liver, skin, salivary glands, stomach, colon, bladder, ovary, and central nervous system.
DEFINITION: Ionizing radiation is the energy released from the disintegration of unstable atomic nuclei during radioactive decay. This type of radiation may originate from X radiation or the emission of various subatomic particles from natural and artificial sources. Some substances decay faster than others and are more or less stable.
Exposure routes: Inhalation, ingestion, direct external exposure
Where found: Ionizing radiation is naturally occurring and artificially produced. It is found in radon (55 percent) and the Earth. Non-natural sources include military weapons, nuclear reactors, and electronic products. Technologically enhanced naturally occurring radioactive materials (TENORMs) concentrate ionizing radiation in solid sludge, water treatment facilities, aluminum oxide reactions, fertilizers, coal ash, concrete aggregates, diagnostic medical procedures, cable insulation, security screening equipment, and equipment used to kill microorganisms in food.
At risk: Children, pregnant women, industry workers, medical personnel, military personnel, residents in high background radiation areas
Etiology and symptoms of associated cancers: Ionizing radiation, regardless of the source, damages deoxyribonucleic acid (DNA, the genetic material) inside cells. Chromosomal breaks, cell mutations, and actual cell transformation can cause the damage—the consequences of this damage range from immediate cell death to malignant cells over time. The ability of ionizing radiation to kill cells explains its use to treat many cancers. Cancer cells divide more rapidly and are more vulnerable to radiation. Thus, ionizing radiation has the ability, when the trajectory of the beam is focused on a tumor, to shrink tumors by killing cells.
Immediate symptoms of exposure vary according to the type of particle, the dose, the length of exposure, and the route of exposure. Radiation sickness, or acute radiation syndrome, results from immediate excessive high-dose exposure. Whole-body penetration damages the cardiovascular and central nervous systems. The blood pressure drops (hypotension), and the brain swells. Nausea, vomiting, convulsions, and confusion will follow. Death is inevitable when exposure is greater than 3,000 rads.
History: In 1896, Henri Becquerel presented his discovery of radioactivity in Paris at the Academy of Sciences. During the 1900s, scientists Marie and Pierre Curie, Dmitry Mendeleyev, and Wilhelm Conrad Röntgen defined the properties of ionizing radiation. Many of the scientists working with ionizing radiation died as a result of their exposures. In 1970, the Environmental Protection Agency (EPA) began regulating ionizing radiation.
Bibliography
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