Basic Calculations for Occupational Safety and Environmental Health Professionals - Mathematics and Statistics for the Environment - page 437

Bremsstrahlung is electromagnetic (x-ray) radiation associated with the deceleration of
charged particles passing through matter.
Contamination is the deposition of radioactive material in any place where it is not wanted.
Controlled area means an area, outside of a restricted area but inside the site boundary, access
to which can be limited by the licensee for any reason.
Counts per minute (cpm) is the number of nuclear transformations from radioactive decay
able to be detected by a counting instrument in a one minute time interval.
Curie (Ci) is a unit of activity equal to 37 billion disintegrations per second.
Declared pregnant woman means a woman who has voluntary informed her employer, in
writing, of her pregnancy and the estimated date of conception.
Disintegrations per minute (dpm) is the number of nuclear transformation from radioactive
decay in a one minute time interval.
Dose equivalent is a quantity of radiation dose expressing all radiation on a common scale
for calculating the effective absorbed dose. The units of dose equivalent are the rem and
sievert (SV).
Dosimeter is a device used to determine the external radiation dose a person has received.
Effective half-life is the length of time required for a radioactive substance in the body to
lose one-half of its activity present through a combination of biological elimination and
radioactive decay.
Exposure means the amount of ionization in air from x-rays and gamma rays.
Extremity means hand, elbow, and arm below the elbow, foot, knee, or leg below the knee.
Gamma rays are very penetrating electromagnetic radiations emitted from a nucleus and an
atom during radioactive decay.
Half-life is the length of time required for a radioactive substance to lose one-half of its activ-
ity by radioactive decay.
Limits (dose limits) means the permissible upper bounds of radiation doses.
Permitted worker is a laboratory worker who does not work with radioactive materials but
works in a radiation laboratory.
Photon means a type of radiation in the form of an electromagnetic wave.
Rad is a unit of radiation absorbed dose. One rad is equal to 100 ergs per gram.
Radioactive decay is the spontaneous process of unstable nuclei in an atom disintegrating into
stable nuclei, releasing radiation in the process.
Radiation (ionizing radiation) means alpha particles, beta particles, gamma rays, x-rays, neu-
trons, high-speed electrons, high-speed protons, and other particles capable of producing
ions.
Radiation workers are those personnel listed on the Authorized User Form of the supervisor
to conduct work with radioactive materials.
Radioisotope is a radioactive nuclide of a particular element.
Rem is a unit of dose equivalent. One rem is approximately equal to one rad of beta, gamma,
or x-ray radiation, or 1/20 of alpha radiation.
Restricted area means an area, access to which is limited by the licensee for the purpose
of protecting individuals against undue risks from exposure to radiation and radioactive
materials.
Roentgen is a unit of radiation exposure. One roentgen is equal to 0.00025 Coulombs of elec-
trical charge per kilogram of air.
Thermoluminescent dosimeter (TLD) is a dosimeter worn by radiation workers to measure
their radiation dose. The TLD contains crystalline material which stores a fraction of the
absorbed ionizing radiation and releases this energy in the form of light photons when
heated.
Total effective dose equivalent (TEDE) means the sum of the deep-dose equivalent (for exter-
nal exposures) and the committed effective dose equivalent (for internal exposures).