Ogólny patomechanizm choroby popromiennej

Komentarze

Transkrypt

Ogólny patomechanizm choroby popromiennej
Choroba popromienna z Wikipedii
http://pl.wikipedia.org/wiki/Choroba_popromienna
Nieokreślone skutki promieniowania
ICD-10:
T66
T66.0 {{{X.0}}}
T66.1 {{{X.1}}}
T66.2 {{{X.2}}}
T66.3 {{{X.3}}}
T66.4 {{{X.4}}}
T66.5 {{{X.5}}}
T66.6 {{{X.6}}}
T66.7 {{{X.7}}}
T66.8 {{{X.8}}}
T66.9 {{{X.9}}}
Ten artykuł wymaga uzupełnienia źródeł podanych informacji.
Aby uczynić go weryfikowalnym, naleŜy podać przypisy do materiałów opublikowanych w
wiarygodnych źródłach.
Japonka z oparzeniami od promieniowania cieplnego w wyniku wybuchu bomby atomowej w
1945.
Choroba popromienna - ogólna nazwa chorobowych zmian ogólnoustrojowych
powodowanych przez promieniowanie jonizujące oddziałujące na całe (lub prawie całe) ciało.
Zwykle przyczyną choroby popromiennej jest ekspozycja na nadmierne dawki
promieniowania w następstwie wypadków radiacyjnych (np. wskutek wadliwego działania
reaktora jądrowego lub uszkodzenia systemu ochrony przy pracy z urządzeniami
1
generującymi promieniowanie rentgenowskie), a w przeszłości naraŜenie na promieniowanie
przy wybuchu atomowym lub termojądrowym. Choroba popromienna moŜe być takŜe
skutkiem pochłonięcia pierwiastków i izotopów promieniotwórczych (drogą doustną lub
wziewną), takŜe tych po wybuchu jądrowym (opad promieniotwórczy). Mianem choroby
popromiennej nie nazywa się miejscowych skutków oddziaływania promieniowania
jonizującego, takich jak oparzenia popromienne czy martwicy tkanek wywoływanych przez
lecznicze stosowanie promieniowania w leczeniu onkologicznym z wykorzystaniem
radioterapii.
W zaleŜności od wielkości dawki promieniowania, czasu jej pochłonięcia i indywidualnej
podatności, choroba popromienna moŜe mieć przebieg ostry lub przewlekły.
Spis treści
•
•
•
•
•
•
1 Ostra choroba popromienna
o 1.1 Postać subkliniczna
o 1.2 Postać hematologiczna
o 1.3 Postać jelitowa
o 1.4 Postać mózgowa
o 1.5 Postać enzymatyczna
2 Przewlekła choroba popromienna
3 Ogólny patomechanizm choroby popromiennej
4 Środki radiomimetyczne
5 Zobacz teŜ
6 Przypisy
Ostra choroba popromienna [edytuj]
Objawy ostrej choroby popromiennej występują w kilka do kilkudziesięciu godz. po
napromieniowaniu. Im krótszy jest okres utajenia, tym cięŜszy przebieg choroby.
Postać subkliniczna [edytuj]
Pochłonięta dawka: 0.5 Gy - 2 Gy
Objawy: ogólne osłabienie, zmniejszenie ilości limfocytów we krwi obwodowej (limfopenia),
występujące kilkanaście dni po napromieniowaniu
Bezpośrednia przyczyna: depresja narządów limfatycznych (limfocyty są najbardziej
promieniowraŜliwymi komórkami u człowieka)
Śmiertelność u człowieka: 0%
Postać hematologiczna [edytuj]
2
Pochłonięta dawka: 2 Gy - 4 Gy
Objawy: ogólne osłabienie, zmniejszenie ilości limfocytów we krwi obwodowej (limfopenia),
występujące kilka dni po napromieniowaniu, później pojawia się niedokrwistość i obniŜenie
odporności ustroju, niekiedy skaza krwotoczna
Bezpośrednia przyczyna: depresja szpiku
Śmiertelność u człowieka: do 25% chorych
Postać jelitowa [edytuj]
Pochłonięta dawka: 4 Gy - 8 Gy
Objawy: dominują objawy ze strony przewodu pokarmowego, z charakterystycznymi
krwawymi biegunkami, skaza krwotoczna oraz zaburzenia gospodarki wodno-elektrolitowej z
obrzękami. Objawy pojawiają się wkrótce po napromieniowaniu, najpóźniej do kilkunastu
godzin
Bezpośrednia przyczyna: popromienne uszkodzenie nabłonka przewodu pokarmowego z
pojawieniem się owrzodzeń
Śmiertelność u człowieka: 50- 100% chorych
Postać mózgowa [edytuj]
Usta męŜczyzny 21 dni po ekspozycji, w której otrzymał dawkę 10-20 Gy. Widocze
uszkodzenia skóry, warg i języka.
Pochłonięta dawka: 8 Gy - 50 Gy
Objawy: drgawki, utrata przytomności wkrótce po napromieniowaniu
Bezpośrednia przyczyna: uszkodzenie przewodnictwa nerwowego, zwłaszcza synaptycznego
Śmiertelność: 100% napromienionych (jest to postać obserwowana u zwierząt
eksperymentalnych, u człowieka moŜe być ona obserwowana przy wypadkach radiacyjnych,
przy bardzo duŜej dawce pochłoniętej)
3
Postać enzymatyczna [edytuj]
Pochłonięta dawka: powyŜej 50 Gy
Objawy: utrata przytomności, prawie natychmiastowa śmierć "pod promieniami"
Bezpośrednia przyczyna: zablokowanie aktywności enzymatycznej w wyniku bezpośredniego
rozerwania wiązań chemicznych białek enzymatycznych przez kwanty promieniowania
jonizującego (tzw. efekt tarczy)
Śmiertelność: 100% napromienionych (jest to postać obserwowana u zwierząt
eksperymentalnych, poddanych napromienieniu o bardzo duŜej mocy). Ocenia się, Ŝe
dwukrotnie w wypadkach radiacyjnych ludzie ulegli napromieniowaniu dawką powyŜej 50 Sv
(>5000 REM). W wypadku w Wood River, stanie Rhode Island (Stany Zjednoczone) 24 lipca
1964 jeden z pracowników otrzymał dawkę 100 Sv (10 000 REM) i przeŜył 49 godzin po
ekspozycji, a operator, który otrzymał pomiędzy 60-180 Sv (18 000 REM) na górną cześć
ciała w wypadku w Los Alamos, stanie Nowy Meksyk (Stany Zjednoczone) 30 grudnia 1958
przeŜył 36 godzin[1].
Przewlekła choroba popromienna [edytuj]
Mianem przewlekłej choroby popromiennej określa się odległe skutki jednorazowego
napromieniowania, bądź będące efektem długotrwałego naraŜenia na powtarzające się dawki
promieniowania. Ujawniają się one po kilku-kilkunastu latach. Do głównych jej skutków
naleŜą:
•
•
•
•
•
•
zwiększona zapadalność na nowotwory złośliwe (zwłaszcza nowotwory układu
krwiotwórczego: białaczki i chłoniaki oraz nowotwory tarczycy, układu kostnego a
takŜe glejaki).
przyspieszone starzenie się i skrócenie Ŝycia
bezpłodność (zwykle przemijająca)
uszkodzenia genomu komórek płciowych (zwiększona liczba wad wrodzonych u
potomstwa)
zaburzenia hormonalne
zaćma
Ogólny patomechanizm choroby popromiennej [edytuj]
Promieniowanie jonizujące wnikające do ustroju Ŝywego powoduje radiolizę wody zawartej
w tkankach. Uwolnione w jej wyniku rodniki tlenowe i wodorotlenowe rozrywają wiązania
wodorowe pomiędzy parami zasad purynowych i pirymidynowych w łańcuchach kwasów
nukleinowych (DNA i RNA), powodując uszkodzenie cząsteczki. Skutkiem tego
oddziaływania są mutacje genetyczne lub martwica komórek. Szczególnie wraŜliwe na
oddziaływanie rodników tlenowych i wodorotlenowych są te odcinki DNA które ulegają
procesowi replikacji, a zatem w komórkach które ulegają podziałowi mitotycznemu (znajdują
się w fazie S, G2 lub M cyklu komórkowego). Fakt ten tłumaczy słuszność prawa Bergonie i
Tribondeau, określającego wraŜliwość tkanek na promieniowanie. Prawo to głosi, Ŝe
promieniowraŜliwość tkanek jest wprost proporcjonalna do aktywności proliferacyjnej danej
tkanki i odwrotnie proporcjonalna do stopnia jej zróŜnicowania (dojrzałości).
4
Nadmierna ilość wolnych rodników blokuje wiele enzymów wewnątrzkomórkowych,
zwłaszcza katalazy i peroksydazy.
Przy wyŜszej gęstości promieniowania i wysokiej energii promieniowania (powyŜej 100
keV), istotną rolę w wywołaniu skutków choroby popromiennej odgrywa bezpośrednie
oddziaływanie promieniowania na materię, pod postacią efektu Comptona. UwaŜa się, Ŝe ta
postać oddziaływania ma znaczenie w postaci mózgowej i enzymatycznej choroby
popromiennej.
Środki radiomimetyczne [edytuj]
PowyŜej opisany mechanizm uszkodzenia tkanek, polegający na rozrywaniu wiązań
wodorowych kwasów nukleinowych "naśladują" niektóre substancje chemiczne, nazywane
środkami alkilującymi. Prototypem takiej substancji jest iperyt. Pochodne iperytu
(wykorzystywane jako leki) oraz inne substancje z grupy leków alkilujących są
wykorzystywane w chemioterapii onkologicznej. Objawy uboczne ich stosowania (zwłaszcza
przy wysokim dawkowaniu) do pewnego stopnia mogą przypominać objawy choroby
popromiennej.
Zobacz teŜ [edytuj]
•
przegląd zagadnień z zakresu wojskowości
Przypisy
1. ↑ A Review of Criticality Accidents. 2000. 16 (30. pdf-u).
Przeczytaj teŜ zastrzeŜenia dotyczące pojęć medycznych na Wikipedii!
Wikiprojekt: Nauki medyczne • Portal: Nauki medyczne
Źródło: "http://pl.wikipedia.org/wiki/Choroba_popromienna"
Kategorie: Choroby • Wojska chemiczne • Radiologia • Wpływ promieniowania na zdrowie
5
Radiation poisoning From Wikipedia, the free encyclopedia
http://en.wikipedia.org/wiki/Radiation_poisoning
• Ten things you may not know about images on Wikipedia •
Radiation poisoning
Classification and external
resources
Radiation Hazard symbol.
ICD-10
T66.
ICD-9
990
Radiation poisoning, also called "radiation sickness" or a "creeping dose", is a form of
damage to organ tissue due to excessive exposure to ionizing radiation. The term is generally
used to refer to acute problems caused by a large dosage of radiation in a short period, though
this also has occurred with long term exposure to low level radiation. Many of the symptoms
of radiation poisoning occur as ionizing radiation interferes with cell division. This
interference allows for treatment of cancer cells; such cells are among the fastest-dividing in
the body, and may be destroyed by a radiation dose that adjacent normal cells are likely to
survive.
The clinical name for "radiation sickness" is acute radiation syndrome as described by the
CDC.[1][2][3] A chronic radiation syndrome does exist but is very uncommon; this has been
observed among workers in early radium source production sites and in the early days of the
Soviet nuclear program. A short exposure can result in acute radiation syndrome; chronic
radiation syndrome requires a prolonged high level of exposure.
The use of radionuclides in science and industry is strictly regulated in most countries (in the
U.S. by the Nuclear Regulatory Commission). In the event of an accidental or deliberate
release of radioactive material, either evacuation or sheltering in place will be the
recommended measures.
6
Contents
[hide]
•
•
•
•
•
•
•
•
•
•
1 Measuring radiation dosage
2 Acute (short-term) vs chronic (long-term) effects
3 Exposure
o 3.1 External vs internal exposure
3.1.1 External
3.1.2 Internal
o 3.2 Nuclear warfare
o 3.3 Nuclear reactor accidents
o 3.4 Other accidents
o 3.5 Ingestion and inhalation
3.5.1 Deliberate poisoning
4 Prevention
o 4.1 Time
o 4.2 Distance
o 4.3 Shielding
o 4.4 Reduction of incorporation into the human body
o 4.5 Fractionation of dose
5 Treatment
o 5.1 Whole body vs. part of body exposure
o 5.2 Experimental treatments designed to mitigate the effect on bone marrow
6 Table of exposure levels and symptoms
o 6.1 0.05–0.2 Sv (5–20 REM)
o 6.2 0.2–0.5 Sv (20–50 REM)
o 6.3 0.5–1 Sv (50–100 REM)
o 6.4 1–2 Sv (100–200 REM)
o 6.5 2–3 Sv (200–300 REM)
o 6.6 3–4 Sv (300–400 REM)
o 6.7 4–6 Sv (400–600 REM)
o 6.8 6–10 Sv (600–1,000 REM)
o 6.9 10–50 Sv (1,000–5,000 REM)
o 6.10 More than 50 Sv (>5,000 REM)
7 References
8 Further reading
9 See also
10 External links
[edit] Measuring radiation dosage
The rad is a unit of absorbed radiation dose defined in terms of the energy actually deposited
in the tissue. One rad is an absorbed dose of 0.01 joules of energy per kilogram of tissue. The
more recent SI unit is the gray (Gy), which is defined as 1 joule of deposited energy per
kilogram of tissue. Thus one gray is equal to 100 rad.
To accurately assess the risk of radiation, the absorbed dose energy in rad is multiplied by the
relative biological effectiveness (RBE) of the radiation to get the biological dose equivalent in
7
rems. Rem stands for "Röntgen equivalent in man (sic)." In SI units, the absorbed dose energy
in grays is multiplied by the same RBE to get a biological dose equivalent in sieverts (Sv).
The sievert is equal to 100 rem.
The RBE is a "quality factor," often denoted by the letter Q, which assesses the damage to
tissue caused by a particular type and energy of radiation. For alpha particles Q may be as
high as 20, so that one rad of alpha radiation is equivalent to 20 rem. The Q of neutron
radiation depends on their energy. However, for beta particles, x-rays, and gamma rays, Q is
taken as one, so that the rad and rem are equivalent for those radiation sources, as are the gray
and sievert. See the sievert article for a more complete list of Q values.
[edit] Acute (short-term) vs chronic (long-term) effects
Please help improve this section by expanding it.
Further information might be found on the talk page or at requests for expansion.
Radiation sickness is generally associated with acute exposure and has a characteristic set of
symptoms that appear in an orderly fashion. The symptoms of radiation sickness become
more serious (and the chance of survival decreases) as the dosage of radiation increases.
These effects are described as the deterministic effects of radiation.
Longer term exposure to radiation, at doses less than that which produces serious radiation
sickness, can induce cancer as cell-cycle genes are mutated. If a cancer is radiation-induced,
then the disease, the speed at which the condition advances, the prognosis, the degree of pain,
and every other feature of the disease are not functions of the radiation dose to which the
sufferer is exposed.
Since tumors grow by abnormally rapid cell division, the ability of radiation to disturb cell
division is also used to treat cancer (see radiotherapy), and low levels of ionizing radiation
have been claimed to lower one's risk of cancer (see hormesis).
[edit] Exposure
[edit] External vs internal exposure
[edit] External
External exposure is exposure which occurs when the radioactive source (or other radiation
source) is outside (and remains outside) the organism which is exposed. Below are a series of
three examples of external exposure.
•
•
•
A person who places a sealed radioactive source in their pocket
A space traveller who is irradiated by cosmic rays
A person who is treated for cancer by either teletherapy or brachytherapy. While in
brachytherapy the source is inside the person it is still external exposure because the active
part of the source never comes into direct contact with the biological tissues of the person.
8
A diagram showing a hypothetical animal being irradiated by radioactive contamination (shown in
yellow), being irriadated by an external source (in red) of radiation
One of the key points is that external exposure is often relatively easy to estimate, and if the
irradiated objects do not become radioactive (except for a case where the radiation is an
intense neutron beam which causes activation of the object). It is possible for an object to be
contaminated on the outer surfaces, assuming that no radioactivity enters the object it is still a
case of external exposure and it is normally the case that decontamination is easy (wash the
surface).
A diagram showing a hypothetical animal being irradiated by radioactive contamination (shown in
red) which is present on an external surface such as the skin, this emits radiation (shown in yellow)
which can enter the animal's body
[edit] Internal
Internal exposure is when the radioactive material enters the organism, and the radioactive
atoms become incorporated into the organism. Below are a series of examples of internal
exposure.
•
•
The exposure due to 40K present within a normal person.
The exposure to the ingestion of a soluble radioactive substance, such as 90Sr in cow’s milk.
9
•
A person who is being treated for cancer by means of an open source radiotherapy method
where a radioisotope is used as a drug. A review of this topic was published in 1999.[4]
Because the radioactive material becomes intimately mixed with the affected object it is
often difficult to decontaminate the object or person in a case where internal exposure is
occurring. While some very insoluble materials such as fission products within a uranium
dioxide matrix might never be able to truly become part of an organism, it is normal to
consider such particles in the lungs as a form of internal contamination which results in
internal exposure. The reasoning is that the particles have entered via an orifice and can not
be removed with ease from what the lay person (non biologist) would regard as within the
animal. It is important to note that strictly speaking the contents of the digestive tract and
the air within the lungs are outside the body of a mammal.
A diagram showing a hypothetical animal (after it has evolved into one with an orifice and a lung)
being irradiated by radioactive contamination (shown in red) which is present within its lung, this
emits radiation (shown in yellow) which can enter the animal's body
[edit] Nuclear warfare
Japanese woman suffering burns from thermal radiation after a nuclear bomb explosion in 1945.
Nuclear warfare is more complex because a person can be irradiated by at least three
processes. The first (the major cause of burns) is not caused by ionizing radiation.
10
•
•
•
Thermal burns from infrared heat radiation.
Beta burns from shallow ionizing radiation (this would be from fallout particles; the largest
particles in local fallout would be likely to have very high activities because they would be
deposited so soon after detonation and it is likely that one such particle upon the skin would
be able to cause a localised burn); however, these particles are very weakly penetrating and
have a short range.
Gamma burns from highly penetrating radiation. This would likely cause deep gamma
penetration within the body, which would result in uniform whole body irradiation rather
than only a surface burn. In cases of whole body gamma irradiation (circa 10 Gy) due to
accidents involving medical product irradiators, some of the human subjects have developed
injuries to their skin between the time of irradiation and death.
In the picture on the right, the normal clothing that the woman was wearing would have been
unable to attenuate the gamma radiation and it is likely that any such effect was evenly
applied to her entire body. Beta burns would be likely all over the body due to contact with
fallout, but thermal burns are often on one side of the body as heat radiation does not
penetrate the human body. In addition, the pattern on her clothing has been burnt into the skin.
This is because white fabric reflects more infra-red light than dark fabric. As a result, the skin
close to dark fabric is burned more than the skin covered by white clothing.
There is also the risk of internal radiation poisoning by ingestion of fallout particles.
[edit] Nuclear reactor accidents
Radiation poisoning was a major concern after the Chernobyl reactor accident. It is important
to note that in humans the acute effects were largely confined to the accident site. Thirty-one
people died as an immediate result.
Of the 100 million curies (4 exabecquerels) of radioactive material, the short lived radioactive
isotopes such as 131I Chernobyl released were initially the most dangerous. Due to their short
half-lives of 5 and 8 days they have now decayed, leaving the more long-lived 137Cs (with a
half-life of 30.07 years) and 90Sr (with a half-life of 28.78 years) as main dangers.
[edit] Other accidents
Improper handling of radioactive and nuclear materials lead to radiation release and radiation
poisoning. The most serious of these, due to improper disposal of a medical device containing
a radioactive source (teletherapy), occurred in Goiânia, Brazil in 1987. It is noteworthy that
while the majority of accidents involve smaller industrial radioactive sources (typically used
for radiography) a large number of the deaths which have occurred have been due to exposure
to the larger sources used for medical purposes. Here is a link to the Therac-25.
[edit] Ingestion and inhalation
When radioactive compounds enter the human body, the effects are different from those
resulting from exposure to an external radiation source. Especially in the case of alpha
radiation, which normally does not penetrate the skin, the exposure can be much more
damaging after ingestion or inhalation. The radiation exposure is normally expressed as a
committed effective dose equivalent (CEDE).
11
[edit] Deliberate poisoning
See also: Alexander Litvinenko poisoning
On November 23, 2006, Alexander Litvinenko died due to suspected deliberate poisoning
with polonium-210.[5] [6][7] [8] [9]. His is the first case of confirmed death due to such a cause,
although it is also known that there have been other cases of attempted assassination such as
in the cases of KGB defector Nikolay Khokhlov and journalist Yuri Shchekochikhin where
radioactive thallium was used. In addition, an incident occurred in 1990 at Point Lepreau
Nuclear Generating Station where several employees acquired small doses of radiation due to
the contamination of water in the office watercooler with tritium contaminated heavy water
[10] [11]
[edit] Prevention
The best prevention for radiation sickness is to minimize the dose suffered by the human, or
to reduce the dose rate.
[edit] Time
The longer that the humans are subjected to radiation the larger the dose will be. The advice
in the nuclear war manual entitled "Nuclear War Survival Skills" published by Cresson
Kearny in the U.S. was that if one needed to leave the shelter then this should be done as
rapidly as possible to minimize exposure.
In chapter 12 he states that "Quickly putting or dumping wastes outside is not hazardous once
fallout is no longer being deposited. For example, assume the shelter is in an area of heavy
fallout and the dose rate outside is 400 R/hr enough to give a potentially fatal dose in about
an hour to a person exposed in the open. If a person needs to be exposed for only 10 seconds
to dump a bucket, in this 1/360th of an hour he will receive a dose of only about 1 R. Under
war conditions, an additional 1-R dose is of little concern."
In peacetime radiation workers are taught to work as quickly as possible when performing a
task which exposes them to irradiation. For instance, the recovery of a lost radiography source
should be done as quickly as possible.
[edit] Distance
The radiation due to any point source will obey the inverse square law: by doubling the
distance the dose rate is quartered. This is why radiation workers are always taught to pick up
a gamma source with a pair of tongs rather than their hand.
[edit] Shielding
12
By placing a layer of a material which will absorb the radiation between the source and the
human, the dose and dose rate can be reduced. For instance, in the event of a nuclear war, it
would be a good idea to shelter within a building with thick stone walls (Fallout shelter).
During the height of the cold war, fallout shelters were identified in many urban areas. It is
interesting to note that, under some conditions, shielding can increase the dose rate. For
instance, if the electrons from a high energy beta source (such as 32P) strike a lead surface, Xray photons will be generated (radiation produced in this way is known as bremsstrahlung). It
is best for this reason to cover any high Z materials (such as lead or tungsten) with a low Z
material such as aluminium, wood, plastic. This effect can be significant if a person wearing
lead-containing gloves picks up a strong beta source. Also, gamma photons can induce the
emission of electrons from very dense materials by the photoelectric effect; again, by
covering the high Z material with a low Z material, this potential additional source of
exposure to humans can be avoided. Furthermore, gamma rays can scatter off a dense object;
this enables gamma rays to "go around corners" to a small degree. Hence, to obtain a very
high protection factor, the path in/out of the shielded enclosure should have several 90 degree
turns rather than just one.
[edit] Reduction of incorporation into the human body
Potassium iodide (KI), administered orally immediately after exposure, may be used to
protect the thyroid from ingested radioactive iodine in the event of an accident or terrorist
attack at a nuclear power plant, or the detonation of a nuclear explosive. KI would not be
effective against a dirty bomb unless the bomb happened to contain radioactive iodine, and
even then it would only help to prevent thyroid cancer.
[edit] Fractionation of dose
While Devair Alves Ferreira received a large dose during the Goiânia accident of 7.0 Gy, he
lived while his wife received a dose of 5.7 Gy and died. The most likely explanation is that
his dose was fractionated into many smaller doses which were absorbed over a length of time,
while his wife stayed in the house more and was subjected to continuous irradiation without a
break, giving her body less time to repair some of the damage done by the radiation. In the
same way, some of the people who worked in the basement of the wrecked Chernobyl plant
received doses of 10 Gy, but in small fractions, so the acute effects were avoided.
It has been found in radiation biology experiments that if a group of cells are irradiated, then
as the dose increases, the number of cells which survive decreases. It has also been found that
if a population of cells is given a dose before being set aside (without being irradiated) for a
length of time before being irradiated again, then the radiation causes less cell death. The
human body contains many types of cells and the human can be killed by the loss of a single
type of cells in a vital organ. For many short term radiation deaths (3 days to 30 days), the
loss of cells forming blood cells (bone marrow) and the cells in the digestive system
(microvilli which form part of the wall of the intestines are constantly being regenerated in a
healthy human) causes death.
In the graph below, dose/survival curves for a hypothetical group of cells have been drawn,
with and without a rest time for the cells to recover. Other than the recovery time partway
through the irradiation, the cells would have been treated identically.
13
[edit] Treatment
Treatment reversing the effects of irradiation is currently not possible. Anaesthetics and
antiemetics are administered to counter the symptoms of exposure, as well as antibiotics for
countering secondary infections due to the resulting immune system deficiency.
There are also a number of substances used to mitigate the prolonged effects of radiation
poisoning, by eliminating the remaining radioactive materials, post exposure.
[edit] Whole body vs. part of body exposure
In the case of a person who has had only part of their body irradiated then the treatment is
easier, as the human body can tolerate very large exposures to the non-vital parts such as
hands and feet, without having a global effect on the entire body. For instance, if the hands
get a 100 Sv dose which results in the body receiving a dose (averaged over your entire body
of 5 Sv) then the hands may be lost but Radiation poisoning would not occur. The resulting
injury would be described as localized radiation burn.
[edit] Experimental treatments designed to mitigate the effect on bone marrow
Neumune, an androstenediol, was introduced as a radiation countermeasure by the US Armed
Forces Radiobiology Research Institute, and was under joint development with Hollis-Eden
Pharmaceuticals until March, 2007. Neumune is in Investigational New Drug (IND) status
and Phase I trials have been performed.
Some work has been published in which Cordyceps sinensis, a Chinese Herbal Medicine has
been used to protect the bone marrow and digestive systems of mice from whole body
irradation.[12]
14
[edit] Table of exposure levels and symptoms
Dose-equivalents are presently stated in sieverts:
[edit] 0.05–0.2 Sv (5–20 REM)
No symptoms. Potential for cancer and mutation of genetic material, according to the LNT
model: this is disputed (Note: see hormesis). A few researchers contend that low dose
radiation may be beneficial.[13][14][15] 50 mSv is the yearly federal limit for radiation workers
in the United States. In the UK the yearly limit for a classified radiation worker is 20 mSv. In
Canada, the single-year maximum is 50 mSv, but the maximum 5-year dose is only 100 mSv.
Company limits are usually stricter so as not to violate federal limits.[16]
[edit] 0.2–0.5 Sv (20–50 REM)
No noticeable symptoms. Red blood cell count decreases temporarily.
[edit] 0.5–1 Sv (50–100 REM)
Mild radiation sickness with headache and increased risk of infection due to disruption of
immunity cells. Temporary male sterility is possible.
[edit] 1–2 Sv (100–200 REM)
Light radiation poisoning, 10% fatality after 30 days (LD 10/30). Typical symptoms include
mild to moderate nausea (50% probability at 2 Sv), with occasional vomiting, beginning 3 to
6 hours after irradiation and lasting for up to one day. This is followed by a 10 to 14 day latent
phase, after which light symptoms like general illness and fatigue appear (50% probability at
2 Sv). The immune system is depressed, with convalescence extended and increased risk of
infection. Temporary male sterility is common. Spontaneous abortion or stillbirth will occur
in pregnant women.
[edit] 2–3 Sv (200–300 REM)
Moderate radiation poisoning, 35% fatality after 30 days (LD 35/30). Nausea is common
(100% at 3 Sv), with 50% risk of vomiting at 2.8 Sv. Symptoms onset at 1 to 6 hours after
irradiation and last for 1 to 2 days. After that, there is a 7 to 14 day latent phase, after which
the following symptoms appear: loss of hair all over the body (50% probability at 3 Sv),
fatigue and general illness. There is a massive loss of leukocytes (white blood cells), greatly
increasing the risk of infection. Permanent female sterility is possible. Convalescence takes
one to several months.
[edit] 3–4 Sv (300–400 REM)
Severe radiation poisoning, 50% fatality after 30 days (LD 50/30). Other symptoms are
similar to the 2–3 Sv dose, with uncontrollable bleeding in the mouth, under the skin and in
the kidneys (50% probability at 4 Sv) after the latent phase.
[edit] 4–6 Sv (400–600 REM)
15
Acute radiation poisoning, 60% fatality after 30 days (LD 60/30). Fatality increases from
60% at 4.5 Sv to 90% at 6 Sv (unless there is intense medical care). Symptoms start half an
hour to two hours after irradiation and last for up to 2 days. After that, there is a 7 to 14 day
latent phase, after which generally the same symptoms appear as with 3-4 Sv irradiation, with
increased intensity. Female sterility is common at this point. Convalescence takes several
months to a year. The primary causes of death (in general 2 to 12 weeks after irradiation) are
infections and internal bleeding.
[edit] 6–10 Sv (600–1,000 REM)
Acute radiation poisoning, near 100% fatality after 14 days (LD 100/14). Survival depends
on intense medical care. Bone marrow is nearly or completely destroyed, so a bone marrow
transplant is required. Gastric and intestinal tissue are severely damaged. Symptoms start 15
to 30 minutes after irradiation and last for up to 2 days. Subsequently, there is a 5 to 10 day
latent phase, after which the person dies of infection or internal bleeding. Recovery would
take several years and probably would never be complete.
Devair Alves Ferreira received a dose of approximately 7.0 Sv (700 REM) during the Goiânia
accident and survived, partially due to his fractionated exposure.
[edit] 10–50 Sv (1,000–5,000 REM)
The mouth of a man who has suffered a 10 to 20 Gy dose 21 days after the exposure, note that
damage to normal skin, the lips and the tongue can be seen
Acute radiation poisoning, 100% fatality after 7 days (LD 100/7). An exposure this high leads
to spontaneous symptoms after 5 to 30 minutes. After powerful fatigue and immediate nausea
caused by direct activation of chemical receptors in the brain by the irradiation, there is a
period of several days of comparative well-being, called the latent (or "walking ghost")
phase.[citation needed] After that, cell death in the gastric and intestinal tissue, causing massive
diarrhea, intestinal bleeding and loss of water, leads to water-electrolyte imbalance. Death sets
in with delirium and coma due to breakdown of circulation. Death is currently inevitable; the
only treatment that can be offered is pain therapy.
Louis Slotin was exposed to approximately 21 Sv in a criticality accident on 21 May 1946,
and died nine days later on 30 May.
16
[edit] More than 50 Sv (>5,000 REM)
A worker receiving 100 Sv (10,000 REM) in an accident at Wood River, Rhode Island, USA
on 24 July 1964 survived for 49 hours after exposure, and an operator receiving between 60
and 180 Sv (18,000 REM) to his upper body in an accident at Los Alamos, New Mexico,
USA on 30 December 1958 survived for 36 hours; details of this accident can be found on
page 16 (page 30 in the PDF version) of Los Alamos' 2000 Review of Criticality
Accidents.[17]
[edit] References
1. ^ Acute Radiation Syndrome. Centers for Disease Control and Prevention (2005-05-20).
2. ^ Acute Radiation Syndrome, National Center for Environmental Health/Radiation Studies
Branch, 2002-04-09, <http://www.umt.edu/research/Eh/pdf/AcuteRadiationSyndrome.pdf>
3. ^ Acute Radiation Syndrome: A Fact Sheet for Physicians. Centers for Disease Control and
Prevention (2005-03-18).
4. ^ Wynn, Volkert & Hoffman, Timothy (1999), "Therapeutic Radiopharmaceuticals", Chemical
Reviews 99 (9): 2269-2292, doi:10.1021/cr9804386, <http://pubs.acs.org/cgibin/article.cgi/chreay/1999/99/i09/pdf/cr9804386.pdf>
5. ^ "Ushering in the era of nuclear terrorism", by Patterson, Andrew J. MD, PhD, Critical Care
Medicine, v. 35, p.953-954, 2007.
6. ^ "Beyond the Dirty Bomb: Re-thinking Radiological Terror", by James M. Acton; M. Brooke
Rogers; Peter D. Zimmerman, Survival, Volume 49, Issue 3 September 2007, pages 151 - 168
7. ^ "The Litvinenko File: The Life and Death of a Russian Spy", by Martin Sixsmith, True Crime,
2007 ISBN 0-312-37668-5, page 14.
8. ^ Radiological Terrorism: “Soft Killers” by Morten Bremer Mærli, Bellona Foundation
9. ^ Alex Goldfarb and Marina Litvinenko. "Death of a Dissident: The Poisoning of Alexander
Litvinenko and the Return of the KGB." Free Press, New York, 2007. ISBN 978-1416551652.
10. ^ Meeting with past (Russian)
11. ^ Russia's poisoning 'without a poison' – Julian O'Halloran, BBC Radio 4, 6 February
2007.Retrieved on 2007-07-30.
12. ^ Liu, Wei-Chung; Wang, Shu-Chi; Tsai, Min-Lung; Chen, Meng-Chi; Wang, Ya-Chen; Hong, JiHong; McBride, William H. & Chiang (2006-12), "Protection against Radiation-Induced Bone
Marrow and Intestinal Injuries by Cordyceps sinensis, a Chinese Herbal Medicine", Radiation
Research 166 (6): 900-907, DOI 10.1667/RR0670.1
13. ^ Luan, Yuan-Chi. Chronic Radiation Is Beneficial to Human Beings. The Science Advisory
Board.
14. ^ Information on hormesis. Health PHysics Society.[dead link – history]
15. ^ Luckey, Thomas (1999-05). "Nurture With Ionizing Radiation: A Provocative Hypothesis".
Nutrition and Cancer 34 (1): 1-11. doi:10.1207/S15327914NC340101.
16. ^ 10 CFR 20.1201 Occupational dose limits for adults.. United States Nuclear Regulatory
Commission (1991-05-21).
17. ^ A Review of Criticality Accidents, Los Alamos National Laboratory, 2000,
<http://www.orau.org/ptp/Library/accidents/la-13638.pdf>
[edit] Further reading
•
•
Michihiko Hachiya, Hiroshima Diary (Chapel Hill: University of North Carolina, 1955), ISBN 08078-4547-7.
John Hersey, Hiroshima (New York: Vintage, 1946, 1985 new chapter), ISBN 0-679-72103-7.
17
•
•
•
Ibuse Masuji, Black Rain (1969) ISBN 0-87011-364-X
Ernest J. Sternglass, Secret Fallout: low-level radiation from Hiroshima to Three-Mile Island
(1981) ISBN 0-07-061242-0 (online)
Norman Solomon, Harvey Wasserman Killing Our Own: The Disaster of America's Experience
with Atomic Radiation, 1945-1982, New York: Dell, 1982. ISBN 0-385-28537-X, ISBN 0-38528536-1, ISBN 0-440-04567-3 (online)
[edit] See also
•
•
•
•
Hibakusha (Japanese atomic bomb survivors)
Radioactive quackery
List of military nuclear accidents
List of civilian nuclear accidents
[edit] External links
•
•
•
•
•
•
Radiation accidents with multi-organ failure in the United States
List of radiation accidents and other events causing radiation casualties
The criticality accident in Sarov, International Atomic Energy Agency, 2001 — well
documented account of the biological effects of a criticality accident
The Center for Disease Control's fact sheet on Acute Radiation Syndrome
Therac-25 computerized radiation therapy machine accidents
50-KT to 1-MT surface burst thermal burns and radiation doses
[show]
v•d•e
Consequences of external causes (T15-T35, T66-T98, 930-959, 990-995)
[show]
v•d•e
Poisoning and toxicity (T36-T65, 960-989)
Retrieved from "http://en.wikipedia.org/wiki/Radiation_poisoning"
Categories: Causes of death | Radiation health effects | Radioactivity | Radiobiology | Radiology
Hidden categories: All articles with dead external links | Articles with dead external links since
February 2008 | Articles to be expanded since December 2007 | All articles to be expanded | All
articles with unsourced statements | Articles with unsourced statements since August 2007
18
•
•
•
•
•
This page was last modified on 18 May 2008, at 17:33.
All text is available under the terms of the GNU Free Documentation License. (See Copyrights
for details.)
Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a U.S. registered
501(c)(3) tax-deductible nonprofit charity.
Privacy policy
About Wikipedia
Disclaimers
19

Podobne dokumenty