acute radiation syndrome
a combination of clinical syndromes occurring in stages, during a period of hours to weeks after exposure, as injury to various tissues and organs is expressed
wind currents that are created near a nuclear explosion by the updraft accompanying the rise of the fireball and that travel toward the blast
a symptom complex characterized by marked decrease in the number of granulocytes and by lesions of the throat and other mucous membranes, of the gastrointestinal tract, and of the skin
air burst
the explosion of a nuclear weapon at such a height that the expanding fireball does not contact the Earth's surface
alpha particle
a positively charged particle ejected from the nucleus of a radioactive atom, being a high-speed ionized atom of helium. A stream of these particles constitutes alpha rays.
lack of development of an organ or tissue, or of the cellular products from an organ or tissue
acute radiation syndrome
atomic number
the number of protons in an atomic nucleus


becquerel -

abbreviated Bq; 1 becquerel is equal to 1 radioactive disintegration per second
beta particle
an electron emitted from an atomic nucleus during beta decay
bioassay sampling
indirect means of measuring contamination in body tissue or fluids from which body burden is extrapolated
biological agent
microorganisms or their products used to cause disease, incapacitation, death, or material destruction. It may be a live agent or a toxin produced by the agent. A toxin is produced through the metabolic activities of living organisms, including protein or polypeptides. The bioregulators/modulators are biochemical compounds that occur naturally in organisms such as peptides or other small molecules. The pathogen in a biological weapon may be bacteria, mycoplasma, rickettsia, fungi, or virus.
blast wave
a pulse of air in which the pressure increases sharply at the front propagated by the explosion
bomb debris
weapon debris
the process by which a beta particle emits an x ray photon during its interaction with an atomic nucleus
explosion or detonation



the development of cancer; various malignant growths that manifest invasiveness and a tendency to metastasize to another location
the development of cataracts; opacity of the lens causing blindness
cerebral anoxia
absence of oxygen supply to the brain despite adequate perfusion of the tissue by blood
central nervous system
excessive or abnormal accumulation of blood in a tissue or organ
critical mass
the minimum amount of a fissionable material needed to sustain a nuclear chain reaction for a given set of circumstances
critical organ
body organ with an affinity for a particular substance and in which that substance concentrates
abbreviated Ci; the activity of 1 gram of radium-226
a nonantibody protein released by one cell population that acts as an intercellular mediator on another cell population(s). Synthetic cytokines are metabolically active in picomolar concentrations.


decontamination -

reduction or removal of radioactive contamination from a structure, area, object, or person
delayed fallout
radioactive fallout that returns to Earth later than 24 hours after a nuclear detonation; usually ascends into the stratosphere and is distributed worldwide
the shedding of epithelial elements, chiefly of the skin, in scales or small sheets; exfoliation
dose rate
a measure of the amount of ionizing radiation an individual is exposed to per unit of time; commonly expressed in units of gray (or rads) per hour
deterministic effect
one that occurs after a certain dose threshold, with the severity of the effect determined by the dose; example: cataractogenesis
diethylenetriaminepentacetic acid; an effective chelator of plutonium and americium; approved the U.S. Food and Drug Administration as an investigational new drug; license held by REACT/S
dynamic pressure
air pressure that results from the wind behind the shock front of a blast wave


early fallout -

radioactive fallout that returns to Earth within 24 hours after a nuclear detonation; also referred to as local fallout
the presence of abnormally large amounts of fluid in the intercellular tissue
relating to an embryo; an organism in its early developmental stages; in humans, fertilization through 8 weeks
a measure of the number of ionizations produced by gamma or x rays in a volume of air; expressed in units of roentgen


fallout -

the process or phenomenon of the descent to the Earth's surface of particles contaminated with radioactive material from the radioactive cloud produced by a nuclear detonation
capability of reproducing
relating to a fetus; an unborn young from 8 weeks until birth in humans
hot gases that form a luminous sphere after a nuclear explosion
the process of splitting the nucleus of an atom into parts
fission products
a general term for the complex mixture of isotopes produced as a result of nuclear fission
flash burn
a burn caused by excessive exposure of the skin to thermal radiation
former Soviet Union


gamma ray
electromagnetic radiation of short wavelengths emitted by the nucleus of an atom during a nuclear reaction. They consist of high-energy photons, have no mass and no electric charge, travel with the speed of light, and are usually associated with beta rays.
germ cell
a sex cell; a cell from which another organism can develop
any cell containing granules in its cytoplasm, especially a leukocyte (neutrophil, basophil, or eosinophil)
agranulocytosis; a symptom complex consisting of a marked decrease in the number of circulating white blood cells, with lesions of the throat and mucous membranes
abbreviated Gy; a proposed unit of absorbed radiation dose equal to 100 rads


hematopoietic -

pertaining to or effecting the formation of blood cells
the escape of blood from the vessels; hemorrhages, classified according to size: petechiae (pinpoint) or ecchymoses (larger than 1 cm in diamerter)
a highly elevated body temperature
abnormally low blood pressure


ileus -

obstruction of the intestines
induced radiation
radioactivity produced in certain materials as a result of the capture of neutrons, which is accompanied by the formation of unstable nuclei
ingestion pathway
route for internalization of radioactive contaminants; the pathway most accessible for decontamination
inhalation pathway
primary pathway for internalization of radioactive contaminants
the process of stripping electrons from their atomic orbits by radiation
one of two or more atoms whose nuclei have equal numbers of protons but different numbers of neutrons


late effect -

a biological effect that occurs long after radiation exposure ends; example: cancer
a mononuclear leukocyte; chiefly a product of lymphoid tissue andparticipates in humoral and cell-mediated immunity


Mach stem -

the shock front formed by the merging of the primary and reflected shock fronts from an explosion
a birth defect; an abnormal structure or form; example: small head
abnormal smallness of the head; frequently associated with a mental defect
the ratio of sick to well individuals in a community; the sick rate
the ratio of people who die to those who survive irradiation; the death rate


nadir -

the point at which a blood count drops to or closest to zero before beginning to increase
nuclear, biological, chemical
National Council on Radiation Protection and Measurements
nerve agent
a toxic substance that inhibits the cholinesterase enzyme and therefore elevates the acetylcholine level in the body. Symptoms are pinpoint pupils, difficulty focusing, headache, and secretion from the skin and mucous membranes. Nausea, vomiting, and loss of bladder and bowel control lead to severe dehydration. These lead to general muscular fasciculation followed by violent convulsions, coma, respiratory arrest, and death.
an electrically neutral or uncharged particle of matter existing along with protons in the atoms of all elements except the mass 1 isotope of hydrogen
a decrease in the number o f neutrophilic leukocytes in the blood
pertaining to or originating in a hospital
nuclear/radiological agent
traditionally, uranium or plutonium used to produce a nuclear detonation via the fission or fusion process. The fuel is compressed into a given volume to cause super criticality. The major products include blast effects, heat, nuclear radiation, and fallout.
nucleated blood cell
a blood cell that contains a nucleus, to include white cells and reticulocytes
a proton or neutron as part of an atomic nucleus
an atomic nucleus with a specific energy state and specific number of protons and neutrons


overpressure -

the transient pressure that is created by the shock wave of an explosion and exceeds the ambient pressure; expressed in pounds per square inch


pathognomonic -

specifically distinctive or characteristic of a disease or pathologic condition; a sign or symptom on which a diagnosis can be based
perceived threat
a threat that is experienced by a person subjectively and out of proportion to the real threat or physical danger
the engulfing of microorganisms, other cells, and foreign particles by phagocytes
polymorphic nucleated cell
tending to increase blood pressure
a premonitory symptom or precursor; a symptom indicating the onset of a disease
Prussian blue
ferric ferrocyanide; a chemical that is not absorbed by the gastrointestinal system and is an effective means to reduce the body's uptake of cesium, thallium, and rubidium; approved as an investigational new drug by the U.S. Food and Drug Administration with the license held by REAC/TS


radiation dispersal weapon -

any device other than a nuclear exposure device and including weapons or equipment that are specifically designed to disseminate radioactive material to cause destruction, fear, or injury by means of the radiation produced by the decay of such material
radioactive cloud
an all-inclusive term for the cloud of hot gases, smoke, dust, dirt, and debris from a weapon and the environment. The cloud is carried aloft in conjunction with the rising fireball produced by the detonation of a nuclear weapon.
radioactive contamination
radioactive material in an undesirable location such as on structures, areas, objects, or personnel
a radioactive nuclide; one that disintegrates with the emission of corpuscular or electromagnetic radiations
the removal of radioactive particles from a nuclear cloud by precipitation when the cloud is within a rain cloud
radiation dispersal weapon
Radiation Emergency Assistance Center/Training Site
reproductive death
the loss of the ability to reproduce. Many organs must have cells that can reproduce to function. Thus, even though injured cells may remain biologically viable, reproductive death may cause irreversable organ damage.


scavenging -

the selective removal of material from the radioactive cloud by inert substances, such as precipitation, introduced into the fireball
the presence of pathogenic microorganisms (bacteria) or their toxins in the blood or other tissues
systemic disease associated with the presence and persistence of pathogenic microorganisms or their toxins in the blood
shock wave
a pressure pulse that is initiated by the expansion of hot gases produced in an explosion and that is continuously propagated in the medium surrounding the explosion
skin decontamination
removal of radioactive material from the skin
skin permeability
the rate at which the skin absorbs a liquid; expressed as a coefficient. The lower a substance's coefficient, the greater the rate of absorption.
somatic cell
body cell other than a germ cell
stochastic effect
an effect that has no dose threshold and for which the severity of the effect is not dose related although its probability is; example: carcinogenesis
a relatively stable layer of the atmosphere extending from the tropopause to an altitude of about 30 miles
subsurface burst
the explosion of a nuclear weapon beneath the surface of the Earth
a set of symptoms that occur together
acting together to enhance the effect of another force or agent


thermal radiation -

electromagnetic radiation (infrared, visible, and ultraviolet) emitted from the fireball of a nuclear explosion as a consequence of high temperatures
total parenteral nutrition
by injection through some route other than the alimentary canal
total parenteral nutrition
the layer of the Earth's atmosphere that separates the troposphere from the stratosphere
the layer of the Earth's atmosphere extending from the surface up to the tropopause, normally about 25,000 feet in temperate zones and about 55,000 feet in the topics


washout -

the removal of radioactive particles from a nuclear cloud by precipitation when the cloud is below a rain or snow cloud
weapon debris
the highly radioactive material consisting of fission products, various products of neutron capture, unspent fuel, and shards of bomb casing that remain after a nuclear explosion
wound contamination
the presence of a radioactive substance in a wound, whether an abrasion, puncture, or laceration; condition in which the loss of intact skin increases the risk that the contaminant will be absorbed

Glossary from Medical Effects of Ionizing Radiation CD - for additional information consult the Armed Forces Radiobiology Research Institute Web Site at www.afrri.usuhs.mil