Nuclear fallout is the residual radioactive material propelled into the upper atmosphere following a
nuclear blast
Nuclear Blast is a record label and mail order record distributor with subsidiaries in Germany, the United States and Brazil. The label was founded in 1987 by Markus Staiger in Germany. Originally releasing hardcore punk records, the label mov ...
, so called because it "falls out" of the sky after the explosion and the
shock wave
In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a med ...
has passed. It commonly refers to the
radioactive
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is consid ...
dust and ash created when a
nuclear weapon
A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or a combination of fission and fusion reactions ( thermonuclear bomb), producing a nuclear explosion. Both bom ...
explodes. The amount and spread of fallout is a product of the size of the weapon and the altitude at which it is detonated. Fallout may get
entrained with the products of a
pyrocumulus
A flammagenitus cloud, also known as a flammagenitus, pyrocumulus cloud, or fire cloud, is a dense cumuliform cloud associated with fire or volcanic eruptions. A flammagenitus is similar dynamically in some ways to a firestorm, and the two phen ...
cloud and fall as black rain (rain darkened by soot and other particulates, which fell within 30–40 minutes of the
atomic bombings of Hiroshima and Nagasaki
The United States detonated two atomic bombs over the Japanese cities of Hiroshima and Nagasaki on 6 and 9 August 1945, respectively. The two bombings killed between 129,000 and 226,000 people, most of whom were civilians, and remain the onl ...
). This radioactive dust, usually consisting of
fission products mixed with bystanding atoms that are
neutron-activated by exposure, is a form of
radioactive contamination
Radioactive contamination, also called radiological pollution, is the deposition of, or presence of radioactive substances on surfaces or within solids, liquids, or gases (including the human body), where their presence is unintended or undesirab ...
.
Types of fallout
Fallout comes in two varieties. The first is a small amount of carcinogenic material with a long
half-life
Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable ato ...
. The second, depending on the height of detonation, is a large quantity of radioactive dust and sand with a short half-life.
All nuclear explosions produce
fission products, un-fissioned nuclear material, and weapon residues vaporized by the heat of the fireball. These materials are limited to the original mass of the device, but include
radioisotopes
A radionuclide (radioactive nuclide, radioisotope or radioactive isotope) is a nuclide that has excess nuclear energy, making it unstable. This excess energy can be used in one of three ways: emitted from the nucleus as gamma radiation; transferr ...
with long lives.
When the nuclear fireball does not reach the ground, this is the only fallout produced. Its amount can be estimated from the
fission-fusion design and
yield of the weapon.
Global fallout
After the detonation of a weapon at or above the fallout-free altitude (an ''
air burst''),
fission products, un-fissioned nuclear material, and weapon residues vaporized by the heat of the fireball condense into a suspension of particles 10
nm to 20
µm in diameter. This size of
particulate matter, lifted to the
stratosphere
The stratosphere () is the second layer of the atmosphere of the Earth, located above the troposphere and below the mesosphere. The stratosphere is an atmospheric layer composed of stratified temperature layers, with the warm layers of air ...
, may take months or years to settle, and may do so anywhere in the world.
Its radioactive characteristics increase the statistical cancer risk. Elevated atmospheric radioactivity remains measurable after the widespread nuclear testing of the 1950s.
Radioactive fallout has occurred around the world; for example, people have been exposed to
iodine-131
Iodine-131 (131I, I-131) is an important radioisotope of iodine discovered by Glenn Seaborg and John Livingood in 1938 at the University of California, Berkeley. It has a radioactive decay half-life of about eight days. It is associated with nu ...
from atmospheric nuclear testing. Fallout accumulates on vegetation, including fruits and vegetables. Starting from 1951 people may have gotten exposure, depending on whether they were outside, the weather, and whether they consumed contaminated milk, vegetables or fruit. Exposure can be on an intermediate time scale or long term. The intermediate time scale results from fallout that has been put into the troposphere and ejected by precipitation during the first month. Long-term fallout can sometimes occur from deposition of tiny particles carried in the stratosphere. By the time that stratospheric fallout has begun to reach the earth, the radioactivity is very much decreased. Also, after a year it is estimated that a sizable quantity of fission products move from the northern to the southern stratosphere. The intermediate time scale is between 1 and 30 days, with long term fallout occurring after that.
Examples of both intermediate and long term fallout occurred after the 1986
Chernobyl accident, which contaminated over of land in
Ukraine
Ukraine ( uk, Україна, Ukraïna, ) is a country in Eastern Europe. It is the second-largest European country after Russia, which it borders to the east and northeast. Ukraine covers approximately . Prior to the ongoing Russian inv ...
and
Belarus
Belarus,, , ; alternatively and formerly known as Byelorussia (from Russian ). officially the Republic of Belarus,; rus, Республика Беларусь, Respublika Belarus. is a landlocked country in Eastern Europe. It is bordered by R ...
. The main fuel of the reactor was
uranium
Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...
, and surrounding this was graphite, both of which were vaporized by the hydrogen explosion that destroyed the reactor and breached its containment. An estimated 31 people died within a few weeks after this happened, including two plant workers killed at the scene. Although residents were evacuated within 36 hours, people started to complain of vomiting, migraines and other major signs of
radiation sickness. The officials of Ukraine had to close off an 18-mile area. Long term effects included at least 6,000 cases of
thyroid cancer
Thyroid cancer is cancer that develops from the tissues of the thyroid gland. It is a disease in which cells grow abnormally and have the potential to spread to other parts of the body. Symptoms can include swelling or a lump in the neck. C ...
, mainly among children. Fallout spread throughout Western Europe, with Northern Scandinavia receiving a heavy dose, contaminating reindeer herds in Lapland, and salad greens becoming almost unavailable in France.
Local fallout
During detonations of devices at ground level (''
surface burst''), below the fallout-free altitude, or in shallow water, heat
vapor
In physics, a vapor (American English) or vapour (British English and Canadian English; see spelling differences) is a substance in the gas phase at a temperature lower than its critical temperature,R. H. Petrucci, W. S. Harwood, and F. G. Her ...
izes large amounts of earth or water, which is drawn up into the
radioactive cloud
Nuclear fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and the shock wave has passed. It commonly refers to the radioac ...
. This material becomes radioactive when it combines with
fission products or other radio-contaminants, or when it is
neutron-activated.
The table below summarizes the abilities of common isotopes to form fallout. Some radiation taints large amounts of land and
drinking water
Drinking water is water that is used in drink or food preparation; potable water is water that is safe to be used as drinking water. The amount of drinking water required to maintain good health varies, and depends on physical activity level, a ...
causing formal
mutation
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mi ...
s throughout animal and human life.
A surface burst generates large amounts of particulate matter, composed of particles from less than 100
nm to several millimeters in diameter—in addition to very fine particles that contribute to worldwide fallout.
The larger particles spill out of the stem and cascade down the outside of the fireball in a downdraft even as the cloud rises, so fallout begins to arrive near
ground zero
In relation to nuclear explosions and other large bombs, ground zero (also called surface zero) is the point on the Earth's surface closest to a detonation. In the case of an explosion above the ground, ''ground zero'' is the point on the ground ...
within an hour. More than half the total bomb debris lands on the ground within about 24 hours as local fallout.
Chemical properties of the elements in the fallout control the rate at which they are deposited on the ground. Less volatile elements deposit first.
Severe local fallout contamination can extend far beyond the blast and thermal effects, particularly in the case of high yield surface detonations. The ground track of fallout from an explosion depends on the weather from the time of detonation onward. In stronger winds, fallout travels faster but takes the same time to descend, so although it covers a larger path, it is more spread out or diluted. Thus, the width of the fallout pattern for any given dose rate is reduced where the downwind distance is increased by higher winds. The total amount of activity deposited up to any given time is the same irrespective of the wind pattern, so overall casualty figures from fallout are generally independent of winds. But
thunderstorm
A thunderstorm, also known as an electrical storm or a lightning storm, is a storm characterized by the presence of lightning and its acoustic effect on the Earth's atmosphere, known as thunder. Relatively weak thunderstorms are someti ...
s can bring down activity as
rain
Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water f ...
allows fallout to drop more rapidly, particularly if the
mushroom cloud
A mushroom cloud is a distinctive mushroom-shaped flammagenitus cloud of debris, smoke and usually condensed water vapor resulting from a large explosion. The effect is most commonly associated with a nuclear explosion, but any sufficiently ener ...
is low enough to be below ("washout"), or mixed with ("rainout"), the thunderstorm.
Whenever individuals remain in a
radiologically contaminated area, such contamination leads to an immediate external radiation exposure as well as a possible later internal hazard from inhalation and ingestion of radiocontaminants, such as the rather short-lived
iodine-131
Iodine-131 (131I, I-131) is an important radioisotope of iodine discovered by Glenn Seaborg and John Livingood in 1938 at the University of California, Berkeley. It has a radioactive decay half-life of about eight days. It is associated with nu ...
, which is accumulated in the
thyroid
The thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans it is in the neck and consists of two connected lobes. The lower two thirds of the lobes are connected by a thin band of tissue called the thyroid isthmus. The thy ...
.
Factors affecting fallout
Location
There are two main considerations for the location of an explosion: height and surface composition. A nuclear weapon detonated in the air, called an
air burst, produces less fallout than a comparable explosion near the ground. A nuclear explosion in which the fireball touches the ground pulls soil and other materials into the cloud and neutron activates it before it falls back to the ground. An air burst produces a relatively small amount of the highly radioactive heavy metal components of the device itself.
In case of water surface bursts, the particles tend to be rather lighter and smaller, producing less local fallout but extending over a greater area. The particles contain mostly
sea salt
Sea salt is salt that is produced by the evaporation of seawater. It is used as a seasoning in foods, cooking, cosmetics and for preserving food. It is also called bay salt, solar salt, or simply salt. Like mined rock salt, production of sea sa ...
s with some water; these can have a
cloud seeding
Cloud seeding is a type of weather modification that aims to change the amount or type of precipitation that falls from clouds by dispersing substances into the air that serve as cloud condensation or ice nuclei, which alter the microphysical p ...
effect causing local
rainout
A rainout is the process of precipitation causing the removal of radioactive particles from the atmosphere onto the ground, creating nuclear fallout by rain. The rainclouds of the rainout are often formed by the particles of a nuclear explosion it ...
and areas of high local fallout. Fallout from a
seawater
Seawater, or salt water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of seawater has appro ...
burst is difficult to remove once it has soaked into
porous
Porosity or void fraction is a measure of the void (i.e. "empty") spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0% and 100%. Strictly speaking, some tests measure ...
surfaces because the fission products are present as metallic
ion
An ion () is an atom or molecule with a net electrical charge.
The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...
s that chemically bond to many surfaces. Water and detergent washing effectively removes less than 50% of this chemically bonded activity from
concrete
Concrete is a composite material composed of fine and coarse aggregate bonded together with a fluid cement (cement paste) that hardens (cures) over time. Concrete is the second-most-used substance in the world after water, and is the most wi ...
or
steel
Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...
. Complete decontamination requires aggressive treatment like
sandblasting
Sandblasting, sometimes known as abrasive blasting, is the operation of forcibly propelling a stream of abrasive material against a surface under high pressure to smooth a rough surface, roughen a smooth surface, shape a surface or remove su ...
, or acidic treatment. After the ''Crossroads'' underwater test, it was found that wet fallout must be immediately removed from ships by continuous water washdown (such as from the
fire sprinkler
A fire sprinkler or sprinkler head is the component of a fire sprinkler system that discharges water when the effects of a fire have been detected, such as when a predetermined temperature has been exceeded. Fire sprinklers are extensively use ...
system on the decks).
Parts of the sea bottom may become fallout. After the
Castle Bravo
Castle Bravo was the first in a series of high-yield thermonuclear weapon design tests conducted by the United States at Bikini Atoll, Marshall Islands, as part of ''Operation Castle''. Detonated on March 1, 1954, the device was the most powerful ...
test, white dust—contaminated
calcium oxide
Calcium oxide (CaO), commonly known as quicklime or burnt lime, is a widely used chemical compound. It is a white, Caustic (substance), caustic, alkaline, crystalline solid at room temperature. The broadly used term "''lime (material), lime''" co ...
particles originating from pulverized and
calcined
Calcination refers to thermal treatment of a solid chemical compound (e.g. mixed carbonate ores) whereby the compound is raised to high temperature without melting under restricted supply of ambient oxygen (i.e. gaseous O2 fraction of air), gener ...
coral
Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and sec ...
s—fell for several hours, causing
beta burn
A radiation burn is a damage to the skin or other biological tissue and organs as an effect of radiation. The radiation types of greatest concern are thermal radiation, radio frequency energy, ultraviolet light and ionizing radiation.
The mos ...
s and radiation exposure to the inhabitants of the nearby atolls and the crew of the ''
Daigo Fukuryū Maru
was a Japanese tuna fishing boat with a crew of 23 men which was contaminated by nuclear fallout from the United States Castle Bravo thermonuclear weapon test at Bikini Atoll on March 1, 1954.
The crew suffered acute radiation syndrome (ARS ...
'' fishing boat. The scientists called the fallout ''Bikini snow''.
For subsurface bursts, there is an additional phenomenon present called "
base surge
A pyroclastic surge is a fluidised mass of turbulent gas and rock fragments that is ejected during some volcanic eruptions. It is similar to a pyroclastic flow but it has a lower density or contains a much higher ratio of gas to rock, which makes i ...
". The base surge is a cloud that rolls outward from the bottom of the subsiding column, which is caused by an excessive density of dust or water droplets in the air. For underwater bursts, the visible surge is, in effect, a cloud of liquid (usually water) droplets with the property of flowing almost as if it were a homogeneous fluid. After the water evaporates, an invisible base surge of small radioactive particles may persist.
For subsurface land bursts, the surge is made up of small solid particles, but it still behaves like a
fluid
In physics, a fluid is a liquid, gas, or other material that continuously deforms (''flows'') under an applied shear stress, or external force. They have zero shear modulus, or, in simpler terms, are substances which cannot resist any shear ...
. A soil earth medium favors base surge formation in an underground burst. Although the base surge typically contains only about 10% of the total bomb debris in a subsurface burst, it can create larger radiation doses than fallout near the detonation, because it arrives sooner than fallout, before much radioactive decay has occurred.
Meteorological
Meteorological conditions greatly influence fallout, particularly local fallout. Atmospheric winds are able to bring fallout over large areas. For example, as a result of a ''
Castle Bravo
Castle Bravo was the first in a series of high-yield thermonuclear weapon design tests conducted by the United States at Bikini Atoll, Marshall Islands, as part of ''Operation Castle''. Detonated on March 1, 1954, the device was the most powerful ...
'' surface burst of a 15 Mt thermonuclear device at
Bikini Atoll
Bikini Atoll ( or ; Marshallese: , , meaning "coconut place"), sometimes known as Eschscholtz Atoll between the 1800s and 1946 is a coral reef in the Marshall Islands consisting of 23 islands surrounding a central lagoon. After the Seco ...
on March 1, 1954, a roughly cigar-shaped area of the
Pacific
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...
extending over 500 km downwind and varying in width to a maximum of 100 km was severely contaminated. There are three very different versions of the fallout pattern from this test, because the fallout was measured only on a small number of widely spaced Pacific Atolls. The two alternative versions both ascribe the high radiation levels at north
Rongelap
Rongelap Atoll ( Marshallese: , ) is a coral atoll of 61 islands (or motus) in the Pacific Ocean, and forms a legislative district of the Ralik Chain of the Marshall Islands. Its total land area is . It encloses a lagoon with an area of . ...
to a downwind hot spot caused by the large amount of radioactivity carried on fallout particles of about 50–100 micrometres size.
After ''Bravo'', it was discovered that fallout landing on the ocean disperses in the top water layer (above the
thermocline
A thermocline (also known as the thermal layer or the metalimnion in lakes) is a thin but distinct layer in a large body of fluid (e.g. water, as in an ocean or lake; or air, e.g. an atmosphere) in which temperature changes more drastically with ...
at 100 m depth), and the land equivalent dose rate can be calculated by multiplying the ocean dose rate at two days after burst by a factor of about 530. In other 1954 tests, including ''Yankee'' and ''Nectar,'' hot spots were mapped out by ships with submersible probes, and similar hot spots occurred in 1956 tests such as ''Zuni'' and ''Tewa''.
However, the major U.S. "
DELFIC" (Defence Land Fallout Interpretive Code) computer calculations use the natural size distributions of particles in soil instead of the
afterwind sweep-up spectrum, and this results in more straightforward fallout patterns lacking the downwind hot spot.
Snow
Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes.
It consists of frozen crystalline water throughout ...
and
rain
Rain is water droplets that have condensed from atmospheric water vapor and then fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth. It provides water f ...
, especially if they come from considerable heights, accelerate local fallout. Under special meteorological conditions, such as a local rain shower that originates above the radioactive cloud, limited areas of heavy contamination just downwind of a nuclear blast may be formed.
Effects
A wide range of
biological changes may follow the irradiation of animals. These vary from rapid death following high doses of penetrating whole-body radiation, to essentially normal lives for a variable period of time until the development of delayed radiation effects, in a portion of the exposed population, following low dose exposures.
The unit of actual ''exposure'' is the
röntgen, defined in
ionisation
Ionization, or Ionisation is the process by which an atom or a molecule acquires a negative or positive charge by gaining or losing electrons, often in conjunction with other chemical changes. The resulting electrically charged atom or molecu ...
s per unit volume of air. All ionisation based instruments (including
geiger counter
A Geiger counter (also known as a Geiger–Müller counter) is an electronic instrument used for detecting and measuring ionizing radiation. It is widely used in applications such as radiation dosimetry, radiological protection, experimental ph ...
s and
ionisation chamber
The ionization chamber is the simplest type of gas-filled radiation detector, and is widely used for the detection and measurement of certain types of ionizing radiation, including X-rays, gamma rays, and beta particles. Conventionally, the term ...
s) measure exposure. However, effects depend on the energy per unit mass, not the exposure measured in air. A deposit of 1 joule per kilogram has the unit of 1
gray
Grey (more common in British English) or gray (more common in American English) is an intermediate color between black and white. It is a neutral or achromatic color, meaning literally that it is "without color", because it can be composed o ...
(Gy). For 1 MeV energy gamma rays, an exposure of 1 röntgen in air produces a dose of about 0.01 gray (1 centigray, cGy) in water or surface tissue. Because of shielding by the tissue surrounding the bones, the
bone marrow
Bone marrow is a semi-solid tissue found within the spongy (also known as cancellous) portions of bones. In birds and mammals, bone marrow is the primary site of new blood cell production (or haematopoiesis). It is composed of hematopoietic ce ...
only receives about 0.67 cGy when the air exposure is 1 röntgen and the surface skin dose is 1 cGy. Some lower values reported for the amount of radiation that would kill 50% of personnel (the ) refer to bone marrow dose, which is only 67% of the air dose.
Short term
The dose that would be lethal to 50% of a population is a common parameter used to compare the effects of various fallout types or circumstances. Usually, the term is defined for a specific time, and limited to studies of acute lethality. The common time periods used are 30 days or less for most small laboratory animals and to 60 days for large animals and humans. The LD
50 figure assumes that the individuals did not receive other injuries or medical treatment.
In the 1950s, the LD
50 for gamma rays was set at 3.5 Gy, while under more dire conditions of war (a bad diet, little medical care, poor nursing) the LD
50 was 2.5 Gy (250 rad). There have been few documented cases of survival beyond 6 Gy. One person at
Chernobyl
Chernobyl ( , ; russian: Чернобыль, ) or Chornobyl ( uk, Чорнобиль, ) is a partially abandoned city in the Chernobyl Exclusion Zone, situated in the Vyshhorod Raion of northern Kyiv Oblast, Ukraine. Chernobyl is about no ...
survived a dose of more than 10 Gy, but many of the persons exposed there were not uniformly exposed over their entire body. If a person is exposed in a non-homogeneous manner then a given dose (averaged over the entire body) is less likely to be lethal. For instance, if a person gets a hand/low arm dose of 100 Gy, which gives them an overall dose of 4 Gy, they are more likely to survive than a person who gets a 4 Gy dose over their entire body. A hand dose of 10 Gy or more would likely result in loss of the hand. A
British
British may refer to:
Peoples, culture, and language
* British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies.
** Britishness, the British identity and common culture
* British English, ...
industrial
radiographer
Radiographers, also known as radiologic technologists, diagnostic radiographers and medical radiation technologists are healthcare professionals who specialize in the imaging of human anatomy for the diagnosis and treatment of pathology. Radi ...
who was estimated to have received a hand dose of 100 Gy over the course of his lifetime lost his hand because of
radiation dermatitis
A radiation burn is a damage to the skin or other biological tissue and organs as an effect of radiation. The radiation types of greatest concern are thermal radiation, radio frequency energy, ultraviolet light and ionizing radiation.
The most ...
. Most people become ill after an exposure to 1 Gy or more. The
fetus
A fetus or foetus (; plural fetuses, feti, foetuses, or foeti) is the unborn offspring that develops from an animal embryo. Following embryonic development the fetal stage of development takes place. In human prenatal development, fetal deve ...
es of
pregnant
Pregnancy is the time during which one or more offspring develops (gestation, gestates) inside a woman, woman's uterus (womb). A multiple birth, multiple pregnancy involves more than one offspring, such as with twins.
Pregnancy usually occur ...
women are often more vulnerable to radiation and may
miscarry, especially in the first
trimester.
One hour after a surface burst, the radiation from fallout in the
crater region is 30 grays per hour (Gy/h). Civilian
dose rate
A dose rate is quantity of radiation absorbed or delivered per unit time.
It is often indicated in micrograys per hour (µGy/h) or as an equivalent dose rate ḢT in rems per hour (rem/hr) or sieverts per hour (Sv/h).
Dose and dose rate are u ...
s in peacetime range from 30 to 100 µGy per year.
Fallout radiation decays relatively quickly with time. Most areas become fairly safe for travel and decontamination after three to five weeks.
For
yields of up to 10
kt, prompt radiation is the dominant producer of casualties on the battlefield. Humans receiving an acute incapacitating dose (30 Gy) have their performance degraded almost immediately and become ineffective within several hours. However, they do not die until five to six days after exposure, assuming they do not receive any other injuries. Individuals receiving less than a total of 1.5 Gy are not incapacitated. People receiving doses greater than 1.5 Gy become disabled, and some eventually die.
A dose of 5.3 Gy to 8.3 Gy is considered lethal but not immediately incapacitating. Personnel exposed to this amount of radiation have their cognitive performance degraded in two to three hours, depending on how physically demanding the tasks they must perform are, and remain in this disabled state at least two days. However, at that point they experience a recovery period and can perform non-demanding tasks for about six days, after which they relapse for about four weeks. At this time they begin exhibiting symptoms of
radiation poisoning of sufficient severity to render them totally ineffective. Death follows at approximately six weeks after exposure, although outcomes may vary.
Long term
Late or delayed effects of radiation occur following a wide range of doses and dose rates. Delayed effects may appear months to years after
irradiation
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 ...
and include a wide variety of effects involving almost all tissues or organs. Some of the ''possible'' delayed consequences of radiation injury, with the rates above the background prevalence, depending on the absorbed dose, include
carcinogenesis
Carcinogenesis, also called oncogenesis or tumorigenesis, is the formation of a cancer, whereby normal cells are transformed into cancer cells. The process is characterized by changes at the cellular, genetic, and epigenetic levels and abno ...
,
cataract
A cataract is a cloudy area in the lens of the eye that leads to a decrease in vision. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colors, blurry or double vision, halos around light, trouble w ...
formation, chronic
radiodermatitis, decreased
fertility
Fertility is the capability to produce offspring through reproduction following the onset of sexual maturity. The fertility rate is the average number of children born by a female during her lifetime and is quantified demographically. Fertili ...
, and
genetic mutation
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, ...
s.
Presently, the only
teratological
Teratology is the study of abnormalities of physiological development in organisms during their life span. It is a sub-discipline in medical genetics which focuses on the classification of congenital abnormalities in dysmorphology. The related ...
effect observed in humans following nuclear attacks on highly populated areas is
microcephaly
Microcephaly (from New Latin ''microcephalia'', from Ancient Greek μικρός ''mikrós'' "small" and κεφαλή ''kephalé'' "head") is a medical condition involving a smaller-than-normal head. Microcephaly may be present at birth or it ...
which is the only proven malformation, or congenital abnormality, found in the
in utero
''In Utero'' is the third and final studio album by American rock band Nirvana. It was released on September 21, 1993, by DGC Records. After breaking into the mainstream with their second album, ''Nevermind'' (1991), Nirvana hired Steve Albin ...
developing human fetuses present during the Hiroshima and Nagasaki bombings. Of all the pregnant women who were close enough to be exposed to the ''prompt'' burst of intense neutron and gamma doses in the two cities, the total number of children born with
microcephaly
Microcephaly (from New Latin ''microcephalia'', from Ancient Greek μικρός ''mikrós'' "small" and κεφαλή ''kephalé'' "head") is a medical condition involving a smaller-than-normal head. Microcephaly may be present at birth or it ...
was below 50.
No statistically demonstrable increase of congenital malformations was found among the ''later conceived children'' born to survivors of the nuclear detonations at Hiroshima and Nagasaki.
The surviving women of Hiroshima and Nagasaki who could conceive and were exposed to substantial amounts of radiation went on and had children with no higher incidence of abnormalities than the Japanese average.
The
Baby Tooth Survey
The Baby Tooth Survey was initiated by the Greater St. Louis Citizens' Committee for Nuclear Information in conjunction with Saint Louis University and the Washington University School of Dental Medicine as a means of determining the effects of nuc ...
founded by the husband and wife team of physicians Eric Reiss and
Louise Reiss
Louise Marie Zibold Reiss (February 23, 1920 – January 1, 2011) was an American physician who coordinated what became known as the Baby Tooth Survey, in which deciduous teeth from children living in the St. Louis, Missouri, area who were bor ...
, was a research effort focused on detecting the presence of
strontium-90
Strontium-90 () is a radioactive isotope of strontium produced by nuclear fission, with a half-life of 28.8 years. It undergoes β− decay into yttrium-90, with a decay energy of 0.546 MeV. Strontium-90 has applications in medicine and i ...
, a
cancer-causing radioactive isotope created by the more than 400 atomic tests conducted above ground that is absorbed from water and dairy products into the bones and teeth given its chemical similarity to
calcium
Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to ...
. The team sent collection forms to schools in the
St. Louis, Missouri
St. Louis () is the second-largest city in Missouri, United States. It sits near the confluence of the Mississippi River, Mississippi and the Missouri Rivers. In 2020, the city proper had a population of 301,578, while the Greater St. Louis, ...
area, hoping to gather 50,000 teeth each year. Ultimately, the project collected over 300,000 teeth from children of various ages before the project was ended in 1970.
Preliminary results of the Baby Tooth Survey were published in the November 24, 1961, edition of the journal ''
Science
Science is a systematic endeavor that builds and organizes knowledge in the form of testable explanations and predictions about the universe.
Science may be as old as the human species, and some of the earliest archeological evidence for ...
'', and showed that levels of
strontium-90
Strontium-90 () is a radioactive isotope of strontium produced by nuclear fission, with a half-life of 28.8 years. It undergoes β− decay into yttrium-90, with a decay energy of 0.546 MeV. Strontium-90 has applications in medicine and i ...
had risen steadily in children born in the 1950s, with those born later showing the most pronounced increases. The results of a more comprehensive study of the elements found in the teeth collected showed that children born after 1963 had levels of strontium-90 in their baby teeth that was 50 times higher than that found in children born before large-scale atomic testing began. The findings helped convince U.S. President
John F. Kennedy
John Fitzgerald Kennedy (May 29, 1917 – November 22, 1963), often referred to by his initials JFK and the nickname Jack, was an American politician who served as the 35th president of the United States from 1961 until his assassination ...
to sign the
Partial Nuclear Test Ban Treaty
The Partial Test Ban Treaty (PTBT) is the abbreviated name of the 1963 Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and Under Water, which prohibited all test detonations of nuclear weapons except for those conducted ...
with the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...
and
Soviet Union
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national ...
, which ended the above-ground
nuclear weapons testing
Nuclear weapons tests are experiments carried out to determine nuclear weapons' effectiveness, Nuclear weapon yield, yield, and explosive capability. Testing nuclear weapons offers practical information about how the weapons function, how detona ...
that created the greatest amounts of atmospheric nuclear fallout.
[Hevesi, Dennis]
"Dr. Louise Reiss, Who Helped Ban Atomic Testing, Dies at 90"
, ''The New York Times
''The New York Times'' (''the Times'', ''NYT'', or the Gray Lady) is a daily newspaper based in New York City with a worldwide readership reported in 2020 to comprise a declining 840,000 paid print subscribers, and a growing 6 million paid ...
'', January 10, 2011.
The baby tooth survey was a "campaign
hat
A hat is a head covering which is worn for various reasons, including protection against weather conditions, ceremonial reasons such as university graduation, religious reasons, safety, or as a fashion accessory. Hats which incorporate mecha ...
effectively employed a variety of media advocacy strategies" to alarm the public and "galvanized" support against atmospheric nuclear testing, with putting an end to such testing being commonly viewed as a positive outcome for a myriad of other reasons. The survey could not show then at the time, nor in the decades that have elapsed, that the levels of global strontium-90 or fallout in general, were in any way life-threatening, primarily because "50 times the strontium-90 from ''before'' nuclear testing" is a minuscule number, and multiplication of minuscule numbers results in only a slightly larger minuscule number. Moreover, the
Radiation and Public Health Project
Radiation and Public Health Project (RPHP) is a nonprofit educational and scientific organization founded in 1985 by Jay M. Gould, a statistician and epidemiologist, Benjamin A. Goldman, and Ernest Sternglass. The "shoestring organization" with " ...
which currently retains the teeth has had their stance and publications heavily criticized: A 2003 article in ''
The New York Times
''The New York Times'' (''the Times'', ''NYT'', or the Gray Lady) is a daily newspaper based in New York City with a worldwide readership reported in 2020 to comprise a declining 840,000 paid print subscribers, and a growing 6 million paid ...
'' states that the group's work has been controversial and has little credibility with the scientific establishment.
Similarly, in an April 2014 article in ''Popular Science'', Sarah Fecht explains that the group's work, specifically the widely discussed case of
cherry-picking data to suggest that fallout from the
2011 Fukushima accident caused infant deaths in America, is "
junk science
The expression junk science is used to describe scientific data, research, or analysis considered by the person using the phrase to be spurious or fraudulent. The concept is often invoked in political and legal contexts where facts and scientifi ...
", as despite their papers being peer-reviewed, all independent attempts to corroborate their results return findings that are not in agreement with what the organization suggests. The organization had earlier also tried
to suggest the same thing occurred after the 1979 Three Mile Island accident but this was likewise exposed to be without merit. The tooth survey, and the expansion of the organization into attempting the same test-ban approach with US nuclear electric power stations as the new target, is likewise detailed and critically labelled as the "
Tooth Fairy
The Tooth Fairy is a fantasy figure of early childhood in Western and Western-influenced cultures. The folklore states that when children lose one of their baby teeth, they should place it underneath their pillow or on their bedside table and ...
issue" by the
Nuclear Regulatory Commission
The Nuclear Regulatory Commission (NRC) is an independent agency of the United States government tasked with protecting public health and safety related to nuclear energy. Established by the Energy Reorganization Act of 1974, the NRC began operat ...
.
Effects on the environment
In the event of a large-scale nuclear exchange, the effects would be drastic on the environment as well as directly to the human population. Within direct blast zones everything would be vaporized and destroyed. Cities damaged but not completely destroyed would lose their water system due to the loss of power and supply lines rupturing.
Within the local nuclear fallout pattern suburban areas' water supplies would become extremely contaminated. At this point stored water would be the only safe water to use. All surface water within the fallout would be contaminated by falling fission products.
[
Within the first few months of the nuclear exchange the nuclear fallout will continue to develop and detriment the environment. Dust, smoke, and radioactive particles will fall hundreds of kilometers downwind of the explosion point and pollute surface water supplies.][ ]Iodine-131
Iodine-131 (131I, I-131) is an important radioisotope of iodine discovered by Glenn Seaborg and John Livingood in 1938 at the University of California, Berkeley. It has a radioactive decay half-life of about eight days. It is associated with nu ...
would be the dominant fission product within the first few months, and in the months following the dominant fission product would be strontium-90
Strontium-90 () is a radioactive isotope of strontium produced by nuclear fission, with a half-life of 28.8 years. It undergoes β− decay into yttrium-90, with a decay energy of 0.546 MeV. Strontium-90 has applications in medicine and i ...
.[ These fission products would remain in the fallout dust, resulting in rivers, lakes, sediments, and soils being contaminated with the fallout.][
Rural areas' water supplies would be slightly less polluted by fission particles in intermediate and long-term fallout than cities and suburban areas. Without additional contamination, the lakes, reservoirs, rivers, and runoff would be gradually less contaminated as water continued to flow through its system.][
Groundwater supplies such as aquifers would however remain unpolluted initially in the event of a nuclear fallout. Over time the groundwater could become contaminated with fallout particles, and would remain contaminated for over 10 years after a nuclear engagement.][ It would take hundreds or thousands of years for an aquifer to become completely pure. Groundwater would still be safer than surface water supplies and would need to be consumed in smaller doses. Long term, ]cesium-137
Caesium-137 (), cesium-137 (US), or radiocaesium, is a radioactive isotope of caesium that is formed as one of the more common fission products by the nuclear fission of uranium-235 and other fissionable isotopes in nuclear reactors and nuclea ...
and strontium-90 would be the major radionuclides affecting the fresh water supplies.[
The dangers of nuclear fallout do not stop at increased risks of cancer and radiation sickness, but also include the presence of radionuclides in human organs from food. A fallout event would leave fission particles in the soil for animals to consume, followed by humans. Radioactively contaminated milk, meat, fish, vegetables, grains and other food would all be dangerous because of fallout.][
From 1945 to 1967 the U.S. conducted hundreds of nuclear weapon tests.] Atmospheric testing took place over the US mainland during this time and as a consequence scientists have been able to study the effect of nuclear fallout on the environment. Detonations conducted near the surface of the earth irradiated thousands of tons of soil. Of the material drawn into the atmosphere, portions of radioactive material will be carried by low altitude winds and deposited in surrounding areas as radioactive dust. The material intercepted by high altitude winds will continue to travel. When a radiation cloud at high altitude is exposed to rainfall, the radioactive fallout will contaminate the downwind area below.
Agricultural fields and plants will absorb the contaminated material and animals will consume the radioactive material. As a result, the nuclear fallout may cause livestock to become ill or die, and if consumed the radioactive material will be passed on to humans.
The damage to other living organism as a result to nuclear fallout depends on the species. Mammals particularly are extremely sensitive to nuclear radiation, followed by birds, plants, fish, reptiles, crustaceans, insects, moss, lichen, algae, bacteria, mollusks, and viruses.
Climatologist Alan Robock
Alan may refer to:
People
* Alan (surname), an English and Turkish surname
* Alan (given name), an English given name
** List of people with given name Alan
''Following are people commonly referred to solely by "Alan" or by a homonymous name.''
...
and atmospheric and oceanic sciences professor Brian Toon created a model of a hypothetical small-scale nuclear war that would have approximately 100 weapons used. In this scenario, the fires would create enough soot into the atmosphere to block sunlight, lowering global temperatures by more than one degree Celsius. The result would have the potential of creating widespread food insecurity (nuclear famine). Precipitation across the globe would be disrupted as a result. If enough soot was introduced in the upper atmosphere the planet's ozone layer could potentially be depleted, affecting plant growth and human health.
Radiation from the fallout would linger in soil, plants, and food chains for years. Marine food chains are more vulnerable to the nuclear fallout and the effects of soot in the atmosphere.
Fallout radionuclides' detriment in the human food chain is apparent in the lichen-caribou-eskimo studies in Alaska. The primary effect on humans observed was thyroid dysfunction. The result of a nuclear fallout is incredibly detrimental to human survival and the biosphere. Fallout alters the quality of our atmosphere, soil, and water and causes species to go extinct.
Fallout protection
During the Cold War
The Cold War is a term commonly used to refer to a period of geopolitical tension between the United States and the Soviet Union and their respective allies, the Western Bloc and the Eastern Bloc. The term '' cold war'' is used because the ...
, the governments of the U.S., the USSR, Great Britain, and China attempted to educate their citizens about surviving a nuclear attack by providing procedures on minimizing short-term exposure to fallout. This effort commonly became known as Civil Defense
Civil defense ( en, region=gb, civil defence) or civil protection is an effort to protect the citizens of a state (generally non-combatants) from man-made and natural disasters. It uses the principles of emergency operations: prevention, miti ...
.
Fallout protection is almost exclusively concerned with protection from radiation. Radiation from a fallout is encountered in the forms of alpha
Alpha (uppercase , lowercase ; grc, ἄλφα, ''álpha'', or ell, άλφα, álfa) is the first letter of the Greek alphabet. In the system of Greek numerals, it has a value of one. Alpha is derived from the Phoenician letter aleph , whic ...
, beta
Beta (, ; uppercase , lowercase , or cursive ; grc, βῆτα, bē̂ta or ell, βήτα, víta) is the second letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Modern Greek, it represents the voiced labiod ...
, and gamma
Gamma (uppercase , lowercase ; ''gámma'') is the third letter of the Greek alphabet. In the system of Greek numerals it has a value of 3. In Ancient Greek, the letter gamma represented a voiced velar stop . In Modern Greek, this letter re ...
radiation, and as ordinary clothing affords protection from alpha and beta radiation, most fallout protection measures deal with reducing exposure to gamma radiation. For the purposes of radiation shielding, many materials have a characteristic ''halving thickness'': the thickness of a layer of a material sufficient to reduce gamma radiation exposure by 50%. Halving thicknesses of common materials include: 1 cm (0.4 inch) of lead, 6 cm (2.4 inches) of concrete, 9 cm (3.6 inches) of packed earth or 150 m (500 ft) of air. When multiple thicknesses are built, the shielding multiplies. A practical fallout shield is ten halving-thicknesses of a given material, such as 90 cm (36 inches) of packed earth, which reduces gamma ray exposure by approximately 1024 times (210). A shelter built with these materials for the purposes of fallout protection is known as a fallout shelter
A fallout shelter is an enclosed space specially designated to protect occupants from radioactive debris or fallout resulting from a nuclear explosion. Many such shelters were constructed as civil defense measures during the Cold War.
During ...
.
Personal protective equipment
As the nuclear energy sector continues to grow, the international rhetoric surrounding nuclear warfare intensifies, and the ever-present threat of radioactive materials falling into the hands of dangerous people persists, many scientists are working hard to find the best way to protect human organs from the harmful effects of high energy radiation. Acute Radiation Syndrome (ARS) is the most immediate risk to humans when exposed 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 ...
in dosages greater than around 0.1 Gy/hr. Radiation in the low energy spectrum (alpha
Alpha (uppercase , lowercase ; grc, ἄλφα, ''álpha'', or ell, άλφα, álfa) is the first letter of the Greek alphabet. In the system of Greek numerals, it has a value of one. Alpha is derived from the Phoenician letter aleph , whic ...
and beta radiation
A beta particle, also called beta ray or beta radiation (symbol β), 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 ...
) with minimal penetrating power is unlikely to cause significant damage to internal organs. The high penetrating power of gamma
Gamma (uppercase , lowercase ; ''gámma'') is the third letter of the Greek alphabet. In the system of Greek numerals it has a value of 3. In Ancient Greek, the letter gamma represented a voiced velar stop . In Modern Greek, this letter re ...
and neutron radiation
Neutron radiation is a form of ionizing radiation that presents as free neutrons. Typical phenomena are nuclear fission or nuclear fusion causing the release of free neutrons, which then react with nuclei of other atoms to form new isotopes— ...
, however, easily penetrates the skin and many thin shielding mechanisms to cause cellular degeneration in the stem cells found in bone marrow. While full body shielding in a secure fallout shelter as described above is the most optimal form of radiation protection, it requires being locked in a very thick bunker for a significant amount of time. In the event of a nuclear catastrophe of any kind, it is imperative to have mobile protection equipment for medical and security personnel to perform necessary containment, evacuation, and any number of other important public safety objectives. The mass of the shielding material required to properly protect the entire body from high energy radiation would make functional movement essentially impossible. This has led scientists to begin researching the idea of partial body protection: a strategy inspired by hematopoietic stem cell transplantation (HSCT). The idea is to use enough shielding material to sufficiently protect the high concentration of bone marrow in the pelvic region, which contains enough regenerative stem cells to repopulate the body with unaffected bone marrow. More information on bone marrow shielding can be found in th
Health Physics Radiation Safety Journal
articl
Selective Shielding of Bone Marrow: An Approach to Protecting Humans from External Gamma Radiation
or in the Organisation for Economic Co-operation and Development (OECD) and the Nuclear Energy Agency (NEA)'s 2015 report
Occupational Radiation Protection in Severe Accident Management.
The seven-ten rule
The danger of radiation from fallout also decreases rapidly with time due in large part to the exponential decay of the individual radionuclides. A book by Cresson H. Kearny presents data showing that for the first few days after the explosion, the radiation dose rate is reduced by a factor of ten for every seven-fold increase in the number of hours since the explosion. He presents data showing that "it takes about seven times as long for the dose rate to decay from 1000 roentgens per hour (1000 R/hr) to 10 R/hr (48 hours) as to decay from 1000 R/hr to 100 R/hr (7 hours)." This is a rule of thumb based on observed data, not a precise relation.
United States government guides for fallout protection
The United States government, often the Office of Civil Defense
The Office of Civil Defense (OCD) was an agency of the United States Department of Defense from 1961–64. It replaced the Office of Civil and Defense Mobilization. The organization was renamed the Defense Civil Preparedness Agency on May 5, 197 ...
in the Department of Defense Department of Defence or Department of Defense may refer to:
Current departments of defence
* Department of Defence (Australia)
* Department of National Defence (Canada)
* Department of Defence (Ireland)
* Department of National Defense (Philipp ...
, provided guides to fallout protection in the 1960s, frequently in the form of booklets. These booklets provided information on how to best survive nuclear fallout. They also included instructions for various fallout shelter
A fallout shelter is an enclosed space specially designated to protect occupants from radioactive debris or fallout resulting from a nuclear explosion. Many such shelters were constructed as civil defense measures during the Cold War.
During ...
s, whether for a family, a hospital, or a school shelter were provided. There were also instructions for how to create an improvised fallout shelter, and what to do to best increase a person's chances for survival if they were unprepared.
The central idea in these guides is that materials like concrete, dirt, and sand are necessary to shield a person from fallout particles and radiation. A significant amount of materials of this type are necessary to protect a person from fallout radiation, so safety clothing cannot protect a person from fallout radiation. However, protective clothing can keep fallout particles off a person's body, but the radiation from these particles will still permeate through the clothing. For safety clothing to be able to block the fallout radiation, it would have to be so thick and heavy that a person could not function.
These guides indicated that fallout shelters should contain enough resources to keep its occupants alive for up to two weeks. Community shelters were preferred over single-family shelters. The more people in a shelter, the greater quantity and variety of resources that shelter would be equipped with. These communities’ shelters would also help facilitate efforts to recuperate the community in the future. Single family shelters should be built below ground if possible. Many different types of fallout shelters could be made for a relatively small amount of money. A common format for fallout shelters was to build the shelter underground, with solid concrete blocks to act as the roof. If a shelter could only be partially underground, it was recommended to mound over that shelter with as much dirt as possible. If a house had a basement, it is best for a fallout shelter to be constructed in a corner of the basement. The center of a basement is where the most radiation will be because the easiest way for radiation to enter a basement is from the floor above. The two of the walls of the shelter in a basement corner will be the basement walls that are surrounded by dirt outside. Cinder blocks filled with sand or dirt were highly recommended for the other two walls. Concrete blocks, or some other dense material, should be used as a roof for a basement fallout shelter because the floor of a house is not an adequate roof for a fallout shelter
A fallout shelter is an enclosed space specially designated to protect occupants from radioactive debris or fallout resulting from a nuclear explosion. Many such shelters were constructed as civil defense measures during the Cold War.
During ...
. These shelters should contain water, food, tools, and a method for dealing with human waste.
If a person did not have a shelter previously built, these guides recommended trying to get underground. If a person had a basement but no shelter, they should put food, water, and a waste container in the corner of the basement. Then items such as furniture should be piled up to create walls around the person in the corner. If the underground cannot be reached, a tall apartment building at least ten miles from the blast was recommended as a good fallout shelter. People in these buildings should get as close to the center of the building as possible and avoid the top and ground floors.
Schools were preferred fallout shelters according to the Office of Civil Defense. Schools, not including universities, contained one-quarter of the population of the United States when they were in session at that time. Schools distribution across the nation reflected the density of the population and were often a best building in a community to act as a fallout shelter. Schools also already had organization with leaders set in place. The Office of Civil Defense recommended altering current schools and the construction of future schools to include thicker walls and roofs, better protected electrical systems, a purifying ventilation system, and a protected water pump. The Office of Civil Defense determined 10 square feet of net area per person were necessary in schools that were to function as a fallout shelter. A normal classroom could provide 180 people with area to sleep. If an attack were to happen, all the unnecessary furniture was to be moved out of the classrooms to make more room for people. It was recommended to keep one or two tables in the room if possible to use as a food-serving station.
The Office of Civil Defense conducted four case studies to find the cost of turning four standing schools into fallout shelters and what their capacity would be. The cost of the schools per occupant in the 1960s were $66.00, $127.00, $50.00, and $180.00. The capacity of people these schools could house as shelters were 735, 511, 484, and 460 respectively.
The US Department of Homeland Security and the Federal Emergency Management Agency in coordination with other agencies concerned with public protection in the aftermath of a nuclear detonation have developed more recent guidance documents that build on the older Civil Defense frameworks. Planning Guidance for Response to a Nuclear Detonation was published in 2022 and provided in-depth analysis and response planning for local government jurisdictions.
Nuclear reactor accident
Fallout can also refer to nuclear accident
A nuclear and radiation accident is defined by the International Atomic Energy Agency (IAEA) as "an event that has led to significant consequences to people, the environment or the facility. Examples include lethal effects to individuals, lar ...
s, although a nuclear reactor
A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat from nu ...
does not explode like a nuclear weapon. The isotopic signature
An isotopic signature (also isotopic fingerprint) is a ratio of non-radiogenic ' stable isotopes', stable radiogenic isotopes, or unstable radioactive isotopes of particular elements in an investigated material. The ratios of isotopes in a sample ...
of bomb fallout is very different from the fallout from a serious power reactor accident (such as Chernobyl
Chernobyl ( , ; russian: Чернобыль, ) or Chornobyl ( uk, Чорнобиль, ) is a partially abandoned city in the Chernobyl Exclusion Zone, situated in the Vyshhorod Raion of northern Kyiv Oblast, Ukraine. Chernobyl is about no ...
or Fukushima
may refer to:
Japan
* Fukushima Prefecture, Japanese prefecture
** Fukushima, Fukushima, capital city of Fukushima Prefecture, Japan
***Fukushima University, national university in Japan
*** Fukushima Station (Fukushima) in Fukushima, Fukushim ...
).
The key differences are in volatility and half-life
Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable ato ...
.
Volatility
The boiling point
The boiling point of a substance is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor.
The boiling point of a liquid varies depending upon the surrounding envir ...
of an element (or its compound
Compound may refer to:
Architecture and built environments
* Compound (enclosure), a cluster of buildings having a shared purpose, usually inside a fence or wall
** Compound (fortification), a version of the above fortified with defensive struc ...
s) is able to control the percentage of that element a power reactor accident releases. The ability of an element to form a solid controls the rate it is deposited on the ground after having been injected into the atmosphere by a nuclear detonation or accident.
Half-life
A half life
Half-life (symbol ) is the time required for a quantity (of substance) to reduce to half of its initial value. The term is commonly used in nuclear physics to describe how quickly unstable atoms undergo radioactive decay or how long stable at ...
is the time it takes half of the radiation of a specific substance to decay. A large amount of short-lived isotopes such as 97Zr are present in bomb fallout. This isotope and other short-lived isotopes are constantly generated in a power reactor, but because the criticality occurs over a long length of time, the majority of these short lived isotopes decay before they can be released.
Preventive measures
Nuclear fallout can occur due to a number of different sources. One of the most common potential sources of nuclear fallout is that of nuclear reactors
A nuclear reactor is a device used to initiate and control a fission nuclear chain reaction or nuclear fusion reactions. Nuclear reactors are used at nuclear power plants for electricity generation and in nuclear marine propulsion. Heat from nu ...
. Because of this, steps must be taken to ensure the risk of nuclear fallout at nuclear reactors is controlled.
In the 1950s and 60's, the United States Atomic Energy Commission
The United States Atomic Energy Commission (AEC) was an agency of the United States government established after World War II by U.S. Congress to foster and control the peacetime development of atomic science and technology. President H ...
(AEC) began developing safety regulations against nuclear fallout for civilian nuclear reactors. Because the effects of nuclear fallout are more widespread and longer lasting than other forms of energy production accidents, the AEC desired a more proactive response towards potential accidents than ever before. One step to prevent nuclear reactor accidents was the Price-Anderson Act. Passed by Congress in 1957, the Price-Anderson Act ensured government assistance above the $60 million covered by private insurance companies in the case of a nuclear reactor accident. The main goal of the Price-Anderson Act was to protect the multi-billion-dollar companies overseeing the production of nuclear reactors. Without this protection, the nuclear reactor industry could potentially come to a halt, and the protective measures against nuclear fallout would be reduced. However, because of the limited experience in nuclear reactor technology, engineers had a difficult time calculating the potential risk of released radiation. Engineers were forced to imagine every unlikely accident, and the potential fallout associated with each accident. The AEC's regulations against potential nuclear reactor fallout were centered on the ability of the power plant to the Maximum Credible Accident, or MCA. The MCA involved a "large release of radioactive isotopes after a substantial meltdown of the reactor fuel when the reactor coolant system failed through a Loss-of-Coolant Accident". The prevention of the MCA enabled a number of new nuclear fallout preventive measures. Static safety systems, or systems without power sources or user input, were enabled to prevent potential human error. Containment buildings, for example, were reliably effective at containing a release of radiation and did not need to be powered or turned on to operate. Active protective systems, although far less dependable, can do many things that static systems cannot. For example, a system to replace the escaping steam of a cooling system with cooling water could prevent reactor fuel from melting. However, this system would need a sensor to detect the presence of releasing steam. Sensors can fail, and the results of a lack of preventive measures would result in a local nuclear fallout. The AEC had to choose, then, between active and static systems to protect the public from nuclear fallout. With a lack of set standards and probabilistic calculations, the AEC and the industry became divided on the best safety precautions to use.
This division gave rise to the Nuclear Regulatory Commission
The Nuclear Regulatory Commission (NRC) is an independent agency of the United States government tasked with protecting public health and safety related to nuclear energy. Established by the Energy Reorganization Act of 1974, the NRC began operat ...
, or NRC. The NRC was committed to 'regulations through research', which gave the regulatory committee a knowledge bank of research on which to draw their regulations. Much of the research done by the NRC sought to move safety systems from a deterministic viewpoint into a new probabilistic approach. The deterministic approach sought to foresee all problems before they arose. The probabilistic approach uses a more mathematical approach to weigh the risks of potential radiation leaks. Much of the probabilistic safety approach can be drawn from the radiative transfer
Radiative transfer is the physical phenomenon of energy transfer in the form of electromagnetic radiation. The propagation of radiation through a medium is affected by absorption, emission, and scattering processes. The equation of radiative trans ...
theory in Physics
Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...
, which describes how radiation travels in free space and through barriers. Today, the NRC is still the leading regulatory committee on nuclear reactor power plants.
Determining extent of nuclear fallout
The International Nuclear and Radiological Event Scale
The International Nuclear and Radiological Event Scale (INES) was introduced in 1990 by the International Atomic Energy Agency (IAEA) in order to enable prompt communication of safety significant information in case of nuclear accidents.
The s ...
(INES) is the primary form of categorizing the potential health and environmental effects of a nuclear or radiological event and communicating it to the public. The scale, which was developed in 1990 by 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 1957 ...
and the Nuclear Energy Agency of the Organization for Economic Co-operation and Development, classifies these nuclear accidents based on the potential impact of the fallout:
* Defence-in-Depth: This is the lowest form of nuclear accidents and refers to events that have no direct impact on people or the environment but must be taken note of to improve future safety measures.
* Radiological Barriers and Control: This category refers to events that have no direct impact on people or the environment and only refer to the damage caused within major facilities.
* People and the Environment: This section of the scale consists of more serious nuclear accidents. Events in this category could potentially cause radiation to spread to people close to the location of the accident. This also includes an unplanned, widespread release of the radioactive material.
The INES scale is composed of seven steps that categorize the nuclear events, ranging from anomalies that must be recorded to improve upon safety measures to serious accidents that require immediate action.
Chernobyl
The 1986 nuclear reactor explosion at Chernobyl
Chernobyl ( , ; russian: Чернобыль, ) or Chornobyl ( uk, Чорнобиль, ) is a partially abandoned city in the Chernobyl Exclusion Zone, situated in the Vyshhorod Raion of northern Kyiv Oblast, Ukraine. Chernobyl is about no ...
was categorized as a Level 7 accident, which is the highest possible ranking on the INES scale, due to widespread environmental and health effects and “external release of a significant fraction of reactor core inventory”. The nuclear accident still stands as the only accident in commercial nuclear power that led to radiation-related deaths. The steam explosion and fires released approximately 5200 PBq, or at least 5 percent of the reactor core, into the atmosphere. The explosion itself resulted in the deaths of two plant workers, while 28 people died over the weeks that followed of severe radiation poisoning. Furthermore, young children and adolescents in the areas most contaminated by the radiation exposure showed an increase in the risk for thyroid cancer
Thyroid cancer is cancer that develops from the tissues of the thyroid gland. It is a disease in which cells grow abnormally and have the potential to spread to other parts of the body. Symptoms can include swelling or a lump in the neck. C ...
, although the stated that "there is no evidence of a major public health impact" apart from that. The nuclear accident also took a heavy toll on the environment, including contamination in urban environments caused by the deposition of radionuclides and the contamination of “different crop types, in particular, green leafy vegetables … depending on the deposition levels, and time of the growing season”.
Three Mile Island
The nuclear meltdown at Three Mile Island
3 is a number, numeral, and glyph.
3, three, or III may also refer to:
* AD 3, the third year of the AD era
* 3 BC, the third year before the AD era
* March, the third month
Books
* ''Three of Them'' (Russian: ', literally, "three"), a 1901 ...
in 1979 was categorized as a Level 5 accident on the INES scale because of the “severe damage to the reactor core” and the radiation leak caused by the incident. Three Mile Island was the most serious accident in the history of American commercial nuclear power plants, yet the effects were different from those of the Chernobyl accident. A study done by the Nuclear Regulatory Commission
The Nuclear Regulatory Commission (NRC) is an independent agency of the United States government tasked with protecting public health and safety related to nuclear energy. Established by the Energy Reorganization Act of 1974, the NRC began operat ...
following the incident reveals that the nearly 2 million people surrounding the Three Mile Island plant “are estimated to have received an average radiation dose of only 1 millirem above the usual background dose”. Furthermore, unlike those affected by radiation in the Chernobyl accident, the development of thyroid cancer in the people around Three Mile Island was “less aggressive and less advanced”.
Fukushima
Like the Three Mile Island incident, the incident at Fukushima
may refer to:
Japan
* Fukushima Prefecture, Japanese prefecture
** Fukushima, Fukushima, capital city of Fukushima Prefecture, Japan
***Fukushima University, national university in Japan
*** Fukushima Station (Fukushima) in Fukushima, Fukushim ...
was initially categorized as a Level 5 accident on the INES scale after a tsunami disabled the power supply and cooling of three reactors, which then suffered significant melting in the days that followed. However, after combining the events at the three reactors rather than assessing them individually, the accident was upgraded to an INES Level 7. The radiation exposure from the incident caused a recommended evacuation for inhabitants up to 30 km away from the plant. However, it was also hard to track such exposure because 23 out of the 24 radioactive monitoring stations were also disabled by the tsunami. Removing contaminated water, both in the plant itself and run-off water that spread into the sea and nearby areas, became a huge challenge for the Japanese government and plant workers. During the containment period following the accident, thousands of cubic meters of slightly contaminated water were released in the sea to free up storage for more contaminated water in the reactor and turbine buildings. However, the fallout from the Fukushima accident had a minimal impact on the surrounding population. According to the Institut de Radioprotection et de Surêté Nucléaire, over 62 percent of assessed residents within the Fukushima prefecture received external doses of less than 1 mSv in the four months following the accident. In addition, comparing screening campaigns for children inside the Fukushima prefecture and in the rest of the country revealed no significant difference in the risk of thyroid cancer.
International nuclear safety standards
Founded in 1974, 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 1957 ...
(IAEA) was created to set forth international standards for nuclear reactor safety. However, without a proper policing force, the guidelines set forth by the IAEA were often treated lightly or ignored completely. In 1986, the disaster at Chernobyl
Chernobyl ( , ; russian: Чернобыль, ) or Chornobyl ( uk, Чорнобиль, ) is a partially abandoned city in the Chernobyl Exclusion Zone, situated in the Vyshhorod Raion of northern Kyiv Oblast, Ukraine. Chernobyl is about no ...
was evidence that international nuclear reactor safety was not to be taken lightly. Even in the midst of the Cold War
The Cold War is a term commonly used to refer to a period of geopolitical tension between the United States and the Soviet Union and their respective allies, the Western Bloc and the Eastern Bloc. The term '' cold war'' is used because the ...
, the Nuclear Regulatory Commission sought to improve the safety of Soviet nuclear reactors. As noted by IAEA Director General Hans Blix
Hans Martin Blix (; born 28 June 1928) is a Sweden, Swedish diplomat and politician for the Liberal People's Party (Sweden), Liberal People's Party. He was Minister for Foreign Affairs (Sweden), Swedish Minister for Foreign Affairs (1978–1979 ...
, "A radiation cloud doesn't know international boundaries." The NRC showed the Soviets the safety guidelines used in the US: capable regulation, safety-minded operations, and effective plant designs. The soviets, however, had their own priority: keeping the plant running at all costs. In the end, the same shift between deterministic safety designs to probabilistic safety designs prevailed. In 1989, the World Association of Nuclear Operators
The World Association of Nuclear Operators (WANO) is a not for profit, International organization, international organisation with a mission to maximize the safety and reliability of the world’s commercial nuclear power plants. The organization ...
(WANO) was formed to cooperate with the IAEA to ensure the same three pillars of reactor safety across international borders. In 1991, WANO concluded (using a probabilistic safety approach) that all former communist-controlled nuclear reactors could not be trusted, and should be closed. Compared to a "Nuclear Marshall Plan
The Marshall Plan (officially the European Recovery Program, ERP) was an American initiative enacted in 1948 to provide foreign aid to Western Europe. The United States transferred over $13 billion (equivalent of about $ in ) in economic re ...
", efforts were taken throughout the 1990s and 2000s to ensure international standards of safety for all nuclear reactors.
See also
* Dirty bomb
A dirty bomb or radiological dispersal device is a radiological weapon that combines radioactive material with conventional explosives. The purpose of the weapon is to contaminate the area around the dispersal agent/conventional explosion with ...
* '' Fallout: An American Nuclear Tragedy''
* ''Fallout Protection
''Fallout Protection: What To Know And Do About Nuclear Attack'' was an official United States federal government booklet released in December 1961 by the United States Department of Defense and the Office of Civil Defense.
The first page of the b ...
''—U.S. government booklet
* Effects of nuclear explosions
The effects of a nuclear explosion on its immediate vicinity are typically much more destructive and multifaceted than those caused by conventional explosives. In most cases, the energy released from a nuclear weapon detonated within the lowe ...
* ''Fallout'' (RTÉ drama)—Irish drama exploring scenarios following a nuclear accident at Sellafield.
* Fallout (series)
* Fallout shelter
A fallout shelter is an enclosed space specially designated to protect occupants from radioactive debris or fallout resulting from a nuclear explosion. Many such shelters were constructed as civil defense measures during the Cold War.
During ...
* Fission product
* Hot particle
A hot particle is a microscopic piece of radioactive material that can become lodged in living tissue and deliver a concentrated dose of radiation to a small area. A controversial theory proposes that hot particles within the body are vastly more ...
* Human radiation experiments
Since the discovery of ionizing radiation, a number of human radiation experiments have been performed to understand the effects of ionizing radiation and radioactive contamination on the human body, specifically with the element plutonium.
Ex ...
* List of nuclear accidents
These are lists of nuclear disasters and radioactive incidents.
Main lists
* List of attacks on nuclear plants
* List of Chernobyl-related articles
* List of civilian nuclear accidents
* List of civilian radiation accidents
* List of cri ...
* Lists of nuclear disasters and radioactive incidents
These are lists of nuclear disasters and radioactive incidents.
Main lists
* List of attacks on nuclear plants
* List of Chernobyl-related articles
* List of civilian nuclear accidents
* List of civilian radiation accidents
* List of ...
* Neutron bomb
A neutron bomb, officially defined as a type of enhanced radiation weapon (ERW), is a low-yield thermonuclear weapon designed to maximize lethal neutron radiation in the immediate vicinity of the blast while minimizing the physical power of the b ...
* Mutation breeding#Radiation breeding
* Nuclear fallout effects on an ecosystem
This article uses Chernobyl as a case study of nuclear fallout effects on an ecosystem.
Chernobyl
Officials used hydrometeorological data to create an image of what the potential nuclear fallout looked like after the Chernobyl disaster in 1986. ...
* Nuclear terrorism
Nuclear terrorism refers to any person or persons detonating a nuclear weapon as an act of terrorism (i.e., illegal or immoral use of violence for a political or religious cause). Some definitions of nuclear terrorism include the sabotage of a ...
* ''Nuclear War Survival Skills
''Nuclear War Survival Skills'' or NWSS, by Cresson Kearny, is a civil defense manual. It contains information gleaned from research performed at Oak Ridge National Laboratory during the Cold War, as well as from Kearny's extensive jungle liv ...
'' by Cresson Kearny Cresson Henry Kearny (; – ) wrote several survival-related books based primarily on research performed at Oak Ridge National Laboratory.
Career
Kearny attended Texas Military Institute in the 1930s, where he became the commanding officer of th ...
* Nuclear weapon design
Nuclear weapon designs are physical, chemical, and engineering arrangements that cause the physics package of a nuclear weapon to detonate. There are three existing basic design types:
* pure fission weapons, the simplest and least technically ...
* Potassium iodide
Potassium iodide is a chemical compound, medication, and dietary supplement. It is a medication used for treating hyperthyroidism, in radiation emergencies, and for protecting the thyroid gland when certain types of radiopharmaceuticals are u ...
* Project GABRIEL
Project GABRIEL was an investigation to gauge the impact of nuclear fallout resulting from nuclear warfare. The United States Atomic Energy Commission surmised that the radioactive isotope strontium-90 (Sr-90) presented the greatest hazard to life ...
* ''Protect and Survive
''Protect and Survive'' was a public information campaign on civil defence. Produced by the British government between 1974 and 1980, it intended to advise the public on how to protect themselves during a nuclear attack. The campaign compris ...
'', a series of booklets and a public information film
Public information films (PIFs) are a series of government-commissioned short films, shown during television advertising breaks in the United Kingdom. The name is sometimes also applied, ''faute de mieux'', to similar films from other countries, ...
series produced for the British government in the 1970s and 1980s.
* Radioactive contamination
Radioactive contamination, also called radiological pollution, is the deposition of, or presence of radioactive substances on surfaces or within solids, liquids, or gases (including the human body), where their presence is unintended or undesirab ...
* Radiation poisoning
* Radiation biology
Radiobiology (also known as radiation biology, and uncommonly as actinobiology) 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. ...
* Radioactive waste
Radioactive waste is a type of hazardous waste that contains radioactive material. Radioactive waste is a result of many activities, including nuclear medicine, nuclear research, nuclear power generation, rare-earth mining, and nuclear weapons r ...
* Radiological weapon
Radiological warfare is any form of warfare involving deliberate radiation poisoning or contamination of an area with radiological sources.
Radiological weapons are normally classified as weapons of mass destruction (WMDs), although radiologica ...
* Joseph Rotblat
Sir Joseph Rotblat (4 November 1908 – 31 August 2005) was a Polish and British physicist. During World War II he worked on Tube Alloys and the Manhattan Project, but left the Los Alamos Laboratory on grounds of conscience after it became ...
* Salted bomb
A salted bomb is a nuclear weapon designed to function as a radiological weapon, producing enhanced quantities of radioactive fallout, rendering a large area uninhabitable. The term is derived both from the means of their manufacture, which invol ...
* ''Survival Under Atomic Attack
''Survival Under Atomic Attack'' was the title of an official United States government booklet released by the Executive Office of the President, the National Security Resources Board (document 130), and the Civil Defense Office. Released at t ...
'', an official U.S. government booklet regarding the effects of a nuclear attack.
References
Further reading
* Glasstone, Samuel and Dolan, Philip J., ''The Effects of Nuclear Weapons (third edition)'', U.S. Government Printing Office, 1977.
Available Online
* ''NATO Handbook on the Medical Aspects of NBC Defensive Operations (Part I – Nuclear)'', Departments of the Army, Navy, and Air Force, Washington, D.C., 1996,
* Smyth, H. DeW., ''Atomic Energy for Military Purposes'', Princeton University Press, 1945. (Smyth Report
The Smyth Report (officially ''Atomic Energy for Military Purposes'') is the common name of an administrative history written by American physicist Henry DeWolf Smyth about the Manhattan Project, the Allied effort to develop atomic bombs du ...
)
* ''The Effects of Nuclear War'', Office of Technology Assessment (May 1979),
Available Online
)
* T. Imanaka, S. Fukutani, M. Yamamoto, A. Sakaguchi and M. Hoshi, ''J. Radiation Research'', 2006, 47, Suppl A121–A127.
* Sheldon Novick, ''The Careless Atom'' (Boston MA: Houghton Mifflin Co., 1969), p. 98
External links
NUKEMAP3D
– a 3D nuclear weapons effects simulator powered by Google Maps. It simulates the effects of nuclear weapons upon geographic areas.
{{DEFAULTSORT:Nuclear Fallout
Aftermath of war
Fallout
Nuclear fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and the shock wave has passed. It commonly refers to the radioac ...
Radiation health effects
Environmental impact of nuclear power
Radiobiology
Radioactive contamination
Fallout
Nuclear fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and the shock wave has passed. It commonly refers to the radioac ...
+
Radiological weapons