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An
acute dose means a person received a
radiation dose over a short period of time.
An
alpha is a particle, emitted from the nucleus
of an atom, that contains two protons and two neutrons. It is
identical to the nucleus of a Helium atom, without the
electrons.
The
Becquerel (Bq) is a unit used to measure a
radioactivity. One Becquerel is that quantity of a radioactive
material that will have 1 transformations in one second. Often
radioactivity is expressed in larger units like: thousands (kBq),
one millions (MBq) or even billions (GBq) of a becquerels. As
a result of having one Becquerel being equal to one
transformation per second, there are 3.7 x 1010 Bq in one
curie.
A
beta is a high speed particle, identical to
an electron, that is emitted from the nucleus of an atom.
A
chronic dose means a person received a
radiation dose over a long period of time.
The
curie (Ci) is a unit used to measure a
radioactivity. One curie is that quantity of a radioactive
material that will have 37,000,000,000 transformations in one
second. Often radioactivity is expressed in smaller units
like: thousandths (mCi), one millionths (uCi) or even
billionths (nCi) of a curie. The relationship between
becquerels and curies is: 3.7 x 1010 Bq in one curie.
Gamma
rays are electromagnetic
waves or photons emitted from the nucleus (center) of an atom.
Alternatively, a gamma ray is "a photon or radiation
quantum emitted spontaneously by a radioactive
substance".
Genetic
effects are effects from
some agent, that are seen in the offspring of the individual
who received the agent. The agent must be encountered
pre-conception.
The
gray (Gy) is a unit used to measure a
quantity called absorbed dose. This relates to the amount of
energy actually absorbed in some material, and is used for any
type of radiation and any material. One gray is equal to one
joule of energy deposited in one kg of a material. The unit
gray can be used for any type of radiation, but it does not't
describe the biological effects of the different radiations.
Absorbed dose is often expressed in terms of hundredths of a
gray, or centi-grays. One gray is equivalent to 100 rads.
Health
Physics is an
interdisciplinary science and its application, for the
radiation protection of humans and the environment. Health
Physics combines the elements of physics, biology, chemistry,
statistics and electronic instrumentation to provide
information that can be used to protect individuals from the
effects of radiation.
Ionizing
radiation is radiation
with enough energy so that during an interaction with an atom,
it can remove tightly bound electrons from their orbits,
causing the atom to become charged or ionized. Examples are
gamma rays and neutrons. Non-ionizing radiation
is radiation without enough energy to remove tightly bound
electrons from their orbits around atoms. Examples are
microwaves and visible light.
Nuclear:
"of, relating to, or utilizing the atomic nucleus, atomic
energy, the atom bomb, or atomic power".
Neutrons
are neutral particles that are normally contained in the
nucleus of all atoms and may be removed by various
interactions or processes like collision and fission.
NORM:
Acronym for "naturally occurring radioactive
material". Typically, uranium or thorium ore.
The
rad (radiation absorbed dose) is a unit used
to measure a quantity called absorbed dose. This relates to
the amount of energy actually absorbed in some material, and
is used for any type of radiation and any material. One rad is
defined as the absorption of 100 ergs per gram of material.
The unit rad can be used for any type of radiation, but it
does not't describe the biological effects of the different
radiations.
Radiation
is energy in transit in the form of high speed particles and
electromagnetic waves. We encounter electromagnetic waves
every day. They make up our visible light, radio and
television waves, ultra violet (UV), and microwaves with a
large spectrum of energies. These examples of electromagnetic
waves do not cause ionizations of atoms because they do not
carry enough energy to separate molecules or remove electrons
from atoms. More simply, radiation is "energy radiated in
the form of particles or waves".
Radiation
sickness: "sickness
that results from exposure to radiation and is commonly marked
by fatigue, nausea, vomiting, loss of teeth and hair, and in
more severe cases by damage to blood-forming tissue with
decrease in red and white blood cells and with bleeding"
Radioactive
contamination is
radioactive material distributed over some area, equipment or
person. It tends to be unwanted in the location where it is,
and has to be cleaned up or decontaminated.
Radioactive
material is any material
that contains radioactive atoms.
Radioactivity
is the spontaneous transformation of an unstable atom and
often results in the emission of radiation. This process is
referred to as a transformation, a decay or a disintegrations
of an atom.
The
rem (roentgen equivalent man) is a unit used
to derive a quantity called equivalent dose. This relates the
absorbed dose in human tissue to the effective biological
damage of the radiation. Not all radiation has the same
biological effect, even for the same amount of absorbed dose.
Equivalent dose is often expressed in terms of thousandths of
a rem, or mrem. To determine equivalent dose (rem), you
multiply absorbed dose (rad) by a quality factor (Q) that is
unique to the type of incident radiation.
The
roentgen (R) is a unit used to measure a
quantity called exposure. This can only be used to describe an
amount of gamma and X-rays, and only in air. One roentgen is
equal to depositing in dry air enough energy to cause 2.58E-4
coulombs per kg. It is a measure of the ionizations of the
molecules in a mass of air. The main advantage of this unit is
that it is easy to measure directly, but it is limited because
it is only for deposition in air, and only for gamma and x
rays.
SI
Prefixes
Many units are broken down into smaller units or expressed as
multiples, using standard metric prefixes. As examples, a
kilobecquerel (kBq) is 1000 becquerels, a millirad (mrad) is
10-3 rad, a microrem (΅rem) is 10-6 rem, a nanogram is
10-9 grams, and a picocurie is a 10-12 curies.
The
sievert (Sv) is a unit used to derive a
quantity called equivalent dose. This relates the absorbed
dose in human tissue to the effective biological damage of the
radiation. Not all radiation has the same biological effect,
even for the same amount of absorbed dose. Equivalent dose is
often expressed in terms of millionths of a sievert, or micro-sievert.
To determine equivalent dose (Sv), you multiply absorbed dose
(Gy) by a quality factor (Q) that is unique to the type of
incident radiation. One sievert is equivalent to 100 rem.
Somatic
effects are effects from
some agent, like radiation that are seen in the individual who
receives the agent.
Stochastic
effects are effects that
occur on a random basis with its effect being independent of
the size of dose. The effect typically has no threshold and is
based on probabilities, with the chances of seeing the effect
increasing with dose. Cancer is a stochastic effect.
Non-stochastic effects are effects that can be
related directly to the dose received. The effect is more
severe with a higher dose, i.e., the burn gets worse as dose
increases. It typically has a threshold, below which the
effect will not occur. A skin burn from radiation is a
non-stochastic effect.
Teratogenic
effects are effects from
some agent, that are seen in the offspring of the individual
who received the agent. The agent must be encountered during
the gestation period.
X-Ray:
"any of the electromagnetic radiations of the same nature
as visible radiation but of an extremely short wavelength less
than 100 angstroms that is produced by bombarding a metallic
target with fast electrons in vacuum or by transition of atoms
to lower energy states and that has the properties of ionizing
a gas upon passage through it, of penetrating various
thicknesses of all solids, of acting on photographic films and
plates as light does, and of causing fluorescent screens to
emit light"
X
Rays are electromagnetic
waves or photons not emitted from the nucleus, but normally
emitted by energy changes in electrons. These energy changes
are either in electron orbital shells that surround an atom or
in the process of slowing down such as in an X-ray machine.
For additional definitions, try:
NRC's
Nuclear Related Terms
Health
Physics Society's Radiation Related Fact Sheets and Terms
Nuclear
Science Terms (LBL)
Low
Dose Radiation Research Program's Glossary of Terms
Bobby's
Radiation Glossary for Students
For
more information on radiation, try:
Radiation
Information Network
The
Canadian Nuclear Safety Commission: http://www.cnsc-ccsn.gc.ca/eng/
Dirty
Bombs: The Threat Revisited: Copy
of an article from Defense Horizons.
Heavy
Urban Search and Rescue: http://www.city.toronto.on.ca/ems/operations/husar.htm
National
Homeland Security Knowledgebase: A huge list of links
for nuclear and radiation preparedness and emergencies. http://www.twotigersonline.com/resources.html#nuclear-radiation-1
Office
of the Fire Marshal, Ontario: http://www.ofm.gov.on.ca/
USA
Today: How a 'dirty' bomb works. Weapons can be
classified into two broad categories: conventional and
unconventional. http://www.usatoday.com/graphics/news/gra/gdirtybomb/frame.htm
U.S.
Nuclear Regulatory Commission: "The Nuclear
Regulatory Commission regulates U.S. commercial nuclear power
plants and the civilian use of nuclear materials." http://www.nrc.gov/
U.S.
Environmental Protection Agency: "EPA is the
primary federal agency for protecting people and the
environment from harmful and avoidable exposure to
radiation." http://www.epa.gov/radiation/
U.S.
Department of Labor, Occupational Safety & Health
Administration: http://www.osha.gov/index.html
U.S.
Department of Energy: "DOEs Nuclear Energy,
Science and Technology (NE) program promotes secure,
competitive and environmentally responsible nuclear
technologies to serve the present and future energy needs of
the United States and the world." http://www.energy.gov/engine/content.do?BT_CODE=NUCLEAR
World
Health Organization: The Ionizing Radiation Web Site http://www.who.int/ionizing_radiation/en/
Marshield:
An experienced and widely proven partner for corporations,
institutions, the military and government seeking a
full-service provider of radiation protection solutions. Web
Site http://www.marshield.com
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