A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
1. A measure of the energy deposited by radiation in a target.
For definitions of the most important such measures, see dose quantities and dose concepts.
2. Absorbed dose, committed equivalent dose, committed effective dose, effective dose, equivalent dose or organ dose, as indicated by the context.
! This is not, in general, the same as the dose actually delivered during the year in question, which could include doses from radionuclides remaining in the body from intakes in previous years, and could exclude doses delivered in future years from intakes during the year in question.
avertable dose: The dose that could be averted if a countermeasure or set of countermeasures were to be applied.
averted dose: The dose prevented by the application of a countermeasure or set of countermeasures, i.e. the difference between the projected dose if the countermeasure(s) had not been applied and the actual projected dose.
collective dose: The total radiation dose incurred by a population.
This is the sum of all of the individual doses to members of the population. If the doses continue for longer than a year, then the annual individual doses must also be integrated over time. Unless otherwise specified, the time over which the dose is integrated is infinite; if a finite upper limit is applied to the time integration, the collective dose is described as ‘truncated’ at that time.
Unless otherwise specified, the relevant dose is normally effective dose (see collective effective dose for the formal definition).
Unit: man sievert (man Sv). This is, strictly, just a sievert, but the unit man sievert is used to distinguish the collective dose from the individual dose which a dosimeter would measure (just as, for example, ‘man hours’ are used to measure the total effort devoted to a task, as opposed to the elapsed time that would be shown by a clock).
Contrasting term: individual dose.
! The BSS definition states that the collective dose is "defined as the product of the number of individuals exposed to a source and their average radiation dose." Strictly, it would be more accurate to say that the collective dose can be expressed in this way, but it is not defined as such — indeed, in order to calculate the average dose it would normally be necessary to calculate the collective dose (by summing the individual doses, and integrating over time if necessary) and divide it by the number of individuals.
committed dose:The lifetime dose expected to result from an intake.
This term partially supersedes dose commitment.
dose commitment: The total dose that would eventually result from an event (e.g. a release of activity), a decision or a finite portion of a practice.
More specific and precise terms, such as committed dose or collective dose should be used as appropriate.
individual dose: The dose incurred by an individual.
For contrast with collective dose.
lifetime dose: The total dose received by an individual during his/her lifetime.
In practice, often approximated as the sum of the annual doses incurred. Because annual doses include committed doses, some parts of some of the annual doses may not actually be delivered within the lifetime of the individual, and therefore this may overestimate the true lifetime dose.
For prospective assessments of lifetime dose, a lifetime is normally interpreted as 70 years.
projected dose: The dose that would be expected to be incurred if a specified countermeasure or set of countermeasures — or, in particular, no countermeasures — were to be taken.
The BSS definition  refers only to the dose that would be received if no countermeasures were to be taken.
residual dose: In a chronic exposure situation, the dose expected to be incurred in the future after intervention has been terminated (or a decision has been taken not to intervene).
dose and dose rate effectiveness factor (DDREF):
The ratio between the risk or radiation detriment per unit effective dose for high doses and/or dose rates and that for low doses and dose rates.
Used in the estimation of risk coefficients for low doses and dose rates from observations and epidemiological findings at high doses and dose rates.
Supersedes dose rate effectiveness factor (DREF).
The product of the absorbed dose at a point in the tissue or organ and the appropriate quality factor for the type of radiation giving rise to the dose.
A measure of the dose to a tissue or organ designed to reflect the amount of harm caused.
A quantity used by the International Commission on Radiation Units and Measurements (ICRU) in defining the operational quantities ambient dose equivalent, directional dose equivalent and personal dose equivalent (see dose equivalent quantities). The quantity dose equivalent has been superseded for radiation protection purposes by equivalent dose. 
dose equivalent quantities:
ambient dose equivalent, H*(d): The dose equivalent that would be produced by the corresponding aligned and expanded field in the ICRU sphere at a depth d on the radius opposing the direction of the aligned field.
Defined at a point in a radiation field. Used as a directly measurable proxy for effective dose for use in monitoring of external exposure.
The recommended value of d for strongly penetrating radiation is 10 mm.
directional dose equivalent, Hc(d,W): The dose equivalent that would be produced by the corresponding expanded field in the ICRU sphere at a depth d on a radius in a specified direction W.
Defined at a point in a radiation field. Used as a directly measurable proxy for equivalent dose in the skin for use in monitoring of external exposure.
The recommended value of d for weakly penetrating radiation is 0.07 mm.
individual dose equivalent, penetrating, Hp(d): See personal dose equivalent.
individual dose equivalent, superficial, Hs(d): See personal dose equivalent.
personal dose equivalent, Hp(d): The dose equivalent in soft tissue below a specified point on the body at an appropriate depth d.
Used in the BSS as a directly measurable proxy for equivalent dose in tissues or organs or (with d = 10 mm) for effective dose, in individual monitoring of external exposure.
The recommended values of d are 10 mm for strongly penetrating radiation and 0.07 mm for weakly penetrating radiation. ‘Soft tissue’ is commonly interpreted as the ICRU sphere.
Recommended by ICRU ,  as a simplification of the two separate terms, individual dose equivalent, penetrating, Hp(d), and individual dose equivalent, superficial, Hs(d) defined in ICRU 39 .
! Although dose rate could, in principle, be defined over any unit of time (e.g. an annual dose is, technically a dose rate), in Agency documents the term dose rate should be used only in the context of short periods of time, e.g. dose per second or dose per hour.
dose rate effectiveness factor (DREF):
The ratio between the risk per unit effective dose for high dose rates and that for low dose rates.
Superseded by dose and dose rate effectiveness factor (DDREF).