ICRP 103 Flashcards
alpha/beta ratio
The dose at which the linear
and quadratic components of cell killing are equal
definition of activity
The expectation value of the number of nuclear transformations occurring in a
given quantity of material per unit time
Activity Median Aerodynamic Diameter (AMAD)
The value of aerodynamic diameter such that 50% of the airborne activity in a
specified aerosol is associated with particles greater than the AMAD
Adaptive response
A post-irradiation cellular response which, typically, serves to increase the
resistance of the cell to a subsequent radiation exposure
Ambient dose equivalent
The dose equivalent at a point in a radiation field that would be produced by
the corresponding expanded and aligned field in the ICRU sphere at a depth of
10 mm on the radius vector opposing the direction of the aligned field
Sievert
Annual intake
The amount of a specified radionuclide entering the human body by ingestion
or inhalation within one year.
Averted dose
The dose prevented or avoided by the application of a protective measure or set
of protective measures
Baseline rates
The annual disease incidence observed in a population in the absence of exposure to the agent under study.
Bioassay
Any procedure used to determine the nature, activity, location, or retention of
radionuclides in the body by in vivo measurement or by in vitro analysis of
material excreted or otherwise removed from the body.
Bystander effect
A response in unirradiated cells that is triggered by signals received from irradiated neighbouring cells.
Categories of exposure
occupational
public
medical
collective effective dose
units: man Sv
sum of effective dose for a subgrouo times number of individuals in subgroup
committed effective dose
The sum of the products of the committed organ or tissue equivalent doses and
the appropriate tissue weighting factors (wT), where s is the integration time in
years following the intake. The commitment period is taken to be 50 years for
adults, and to age 70 years for children.
committed equivalent dose
The time integral of the equivalent dose rate in a particular tissue or organ that
will be received by an individual following intake of radioactive material into
the body by a Reference Person, where s is the integration time in years
derived air concentration
This equals the annual limit on intake, ALI, (of a radionuclide) divided by the
volume of air inhaled by a Reference Person in a working year (i.e., 2.2 103 m3
).
The unit of DAC is Bq m3
.
detriment
The total harm to health experienced by an exposed group and its descendants
as a result of the group’s exposure to a radiation source. Detriment is a multidimensional concept. Its principal components are the stochastic quantities:
probability of attributable fatal cancer, weighted probability of attributable
non-fatal cancer, weighted probability of severe heritable effects, and length
of life lost if the harm occurs.
Detriment-adjusted risk
The probability of the occurrence of a stochastic effect, modified to allow for
the different components of the detriment in order to express the severity of
the consequence(s)
Diagnostic reference level
Used in medical imaging with ioning radiation to indicate whether, in routine
conditions, the patient dose or administered activity (amount of radioactive
material) from a specified procedure is unusually high or low for that procedure.
directional dose equivalent
The dose equivalent at a point in a radiation field that would be produced by
the corresponding expanded field in the ICRU sphere at a depth, d, on a radius
in a specified direction, X. The unit of directional dose equivalent is joule per
kilogram (J kg1
) and its special name is sievert (Sv).
dose modifying factor
ratio of doses with and without modifying agents,
causing the same level of biological effect
Dose and dose-rate effectiveness factor (DDREF)
A judged factor that generalises the usually lower biological effectiveness (per
unit of dose) of radiation exposures at low doses and low dose rates as compared with exposures at high doses and high dose rates.
Dose coefficient
Used as a synonym for dose per unit intake of a radioactive substance, but
sometimes also used to describe other coefficients linking quantities or concentrations of activity to doses or dose rates, such as the external dose rate at a
specified distance above a surface with a deposit of a specified activity per unit
area of a specified radionuclide.
dose commitment
A calculational tool, defined as the infinite time integral of the per caput
dose rate E_ due to a specified event, such as a year of a planned activity
causing discharges
dose equivalent
H=DQ
Q= quality factor for specific radiation type