ICRP Glossary

The ICRP Glossary collects ICRP’s definitive explanations of terms for current use. Some entries include historical descriptions to help readers better understand the term in a particular context.

It is a living document, updated regularly.

Many ICRP publications feature their own glossaries including, for example, highly specialized terms relevant to that specific publication or helpful for a reader to have close at hand, or when introducing new terms to be added to the ICRP Glossary.

Although the ICRP Glossary is not a dictionary, terms already well covered in the Oxford English Dictionary are not included here unless further explanation is needed to understand the way in which these terms are used in ICRP publications.

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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

...

A

• Absolute risk

• Absorbed dose, D

• Absorbed fraction

• Absorption

• Accelerated fractionation

• Acceptance test

• Access control

• Accountability

• Action Level

• Activation

• Active (red) bone marrow

• Activity

• Activity median thermodynamic diameter

• Acute exposure

• Acute radiation sickness (see Acute radiation syndrome)

• Acute radiation syndrome

• Adaptive response

• Additive risk projection model

• Adventitious

• Adventitious source

• Aerodynamic diameter

• Air-kerma rate constant

• Air-kerma, entrance surface

• Air-kerma, incident

• Air-kerma, product

• ALI (see Annual limit on intake)

• Alimentary tract

• Alimentary tract transfer factor

• Alpha decay

• Alveolar-interstitial region

• AMAD (see Activity median aerodynamic diameter)

• Ambient dose equivalent, H*(10)

• Angiogenesis

• Annihilation photons

• Annual dose

• Annual intake

• Annual limit on intake

• Area monitoring

• ARS (see Acute radiation syndrome)

• Attributable risk

• Auger transition

• Authorised discharge

• Authorization

• Authorized limit

• Autoimmune disease

• Autonomy

• Averted dose

B

• Background dose (rate)

• Backscatter factor

• Basal cell

• Baseline disease rates

• BAT (see Best available techniques)

• Beneficence

• Benthic

• Best available techniques

• Beta-minus decay

• Beta-plus decay

• Bioassay

• Biological half-life

• Biomarker

• Biomedical research volunteer

• Bioturbation

• Bone marrow

• Bradycardia

• Branching fraction

• Bronchial region

• Bronchiolar region

• Bystander effect

C

• Cardiac arrhythmias

• Cardiac valve diseases

• Cardiomyopathy

• Cardioverter-defibrillator

• Case–control study

• Cell death

• Charged-particle equilibrium

• Chronic exposure

• Class SR-0 gases

• Class SR-1 gases

• Class SR-2 gases

• Clearance level

• Clonogenic cells

• Clonogenic survival

• Co-expertise

• Cohort study

• Collective dose

• Collective effective dose, S

• Colony

• Committed effective dose

• Committed equivalent dose

• Compartment

• Complex tissues

• Computed tomography dose index

• Connective tissue

• Consequential late effects

• Constancy test

• Contamination

• Coronary heart disease

• Cost-benefit analysis

• Coster-Kronig transition

• Cross section

• Cumulative dose

• Curie

• Cytokines

D

• DAC (see Derived air concentration)

• DD (see Doubling dose)

• DIL (see Derived investigation level)

• DDREF (see Dose and dose-rate effectiveness factor)

• Decay constant

• Decommissioning

• Decontamination

• Decontamination factor

• Deontological Ethics

• Deposition

• Derived air concentration

• Derived investigation level

• Deterministic effect

• Detriment

• Detriment-adjusted risk

• Diastasis

• Dicentric chromosome

• Dichotomous

• Differentiation

• Dignity

• Direct bioassay

• Directional dose equivalent H’(d,Ω)

• Disposal

• Disposal facility

• Distribution coefficient (K_d)

• DNA damage signalling

• Dose (of ionising radiation)

• Dose and dose-rate effectiveness factor

• Dose coefficient

• Dose commitment

• Dose constraint

• Dose conversion coefficient

• Dose conversion convention

• Dose conversion factor

• Dose criteria

• Dose of record (E)

• Dose of record Hp (10)

• Dose equivalent in an organ or tissue

• Dose limit

• Dose modifying factor

• Dose per content function

• Dose per unit intake coefficient

• Dose rate

• Dose rate effectiveness factor

• Dose-threshold hypothesis

• Dose-rate effect

• Dose-response function

• Dose-threshold

• Doubling dose

• DS02

• DS86

E

• EAR (see Excess absolute risk)

• Early normal tissue responses

• Edema

• Effect Dose 50

• Effect modifier

• Effective charge number

• Effective dose, E

• Effective dose equivalent

• Effective half-life

• Electron-capture decay

• Electrophysiology

• Elemental dose

• ELR (i.e. Excess Lifetime Risk, see Lifetime risk estimates)

• Emergency

• Emergency exposure situation

• Emergency plan

• Emergency preparedness

• Emergency procedures

• Endogeneous excretion

• Endosteal tissue (see Endosteum)

• Endosteum

• Environmental exposure

• Environmental radiation protection

• Epigenetic effects

• Epithelium

• Equieffective dose

• Equilibrium equivalent concentration

• Equilibrium factor

• Equity

• Equivalent dose

• ERR (see Excess relative risk)

• Erythropoietin

• Ethics

• Excess absolute risk

• Excess lifetime risk (see Lifetime risk estimates)

• Excess relative risk

• Excretion rate (instantaneous)

• Exempt waste

• Exemption level

• Existing exposure situation

• Expanded and aligned radiation field

• Expanded radiation field

• Exponential survival curve

• Exposure, external or internal

• Exposure (in the context of inhalation)

• Exposure pathway

• Exposure situation

• Extrathoracic airways

F

• Fairness

• Field-size effect (Volume effect)

• Flexible tissues

• Fluence, Φ

• Fluoroscopically guided interventions

• Forbiddenness

• Fractional absorption in the gastrointestinal tract, f₁

• Fractionation

• Fractionation sensitivity

G

• Galactic cosmic radiation

• Gamma ray

• Gastrointestinal syndrome

• Genomic integrity

• Graded approach

• Granulocyte colony-stimulating factor

• Granulocyte-macrophage colony-stimulating factor

• Gray (Gy)

• Growth fraction

• Growth hormone (somatotropin)

H

• Habitual mouth breather

• Habitual nose breather

• Half-life, physical

• HATM (see Human Alimentary Tract Model]

• Hazard

• Health Surveillance

• Heliosphere

• Hereditary effect

• Hierarchical tissues

• High level waste

• High linear energy transfer radiation

• Homologous recombination

• Hormones

• Human Alimentary Tract Model

• Human respiratory tract model

• Hyperbaric oxygen

• Hypertrophic cardiomyopathy

• Hypoplasia

I

• Immune system

• In vivo radiobioassay

• Incidence

• Incidence rate (see Incidence)

• Incident

• Inclusiveness

• Individual decontamination

• Individual monitoring

• Individual-related

• Induced genomic instability

• Informed consent

• Inhalability

• Inner bremsstrahlung

• Institutional control

• Intake

• Intermediate level waste

• Internal conversion electron

• Interphase death

• Intervention Level

• Interventional procedure

• Investigation level

• Iso-effect plots

• Isomers

• Isotropic geometry

• Itinerant (radiation) worker

J

• Justice

• Justification

K

• Kerma, K

• Kerma approximation

• Kp index

L

• Late normal tissue responses

• Latent time/period or latency interval

• LD_50/30

• LET (see *Linear energy transfer)

• Life Span Study

• Lifetime risk

• Lifetime risk estimates

• Limitation of dose

• Lineal energy

• Linear dose response

• Linear energy transfer

• Linear-non-threshold model

• Linear-quadratic dose response model

• LLE (see Lifetime risk estimates)

• Loss of Life Expectancy (see Lifetime risk estimates)

• Low Earth orbit

• Low dose

• Low dose rate

• Low level waste

• Low linear energy transfer radiation

• LSS (see Life Span Study)

• Lymphatic system

M

• Macrophage colony stimulating factor

• Magnetosphere

• Marrow cellularity

• Mass median diameter

• Measured quantity

• Medical exposure

• Member of the public

• Mendelian diseases

• Mitigation

• MMD (see *Mass median diameter)

• Multiplicative risk projection model

• Multistage carcinogenesis model

• Multistage tumorigenesis

• Mutation component

• Myocardial perfusion

• Myocardial stress test

N

• Naturally occurring radioactive material

• Necrosis

• Neurological syndrome

• Neurovascular syndrome

• NHEJ (see Non-homologous end joining)

• Nominal risk coefficient

• Non-homologous end joining

• Non-maleficence

• Non-sphericity parameter

• Non-targeted effects

• Normal tissue complication probability

• Nuclear track detectors

O

• Occupancy factor

• Occupational exposure

• OLINDA/EXM

• Oncogene

• Optimisation

• Organ/tissue absorbed dose

• Organ absorbed dose (see Organ/tissue absorbed dose)

• Organ dose equivalent

• Other (systemic) tissues

• Orphan source

• Oversight

P

• Particle fluence (see Fluence)

• Particle transport

• Particle radiance

• Patient entrance reference point

• Peak skin dose

• Pelagic

• Percutaneous coronary intervention

• Pericarditis

• Personal dose equivalent, H_p(d)

• Phantom

• Pharynx

• Planned exposure situation

• Platelet-derived growth factor

• PLDR (see Potentially lethal damage repair)

• Pooled analysis

• Population risk

• Potential alpha energy concentration

• Potential exposure

• Potentially lethal damage repair

• Practical radiological protection culture

• Prevailing circumstances

• Principle of application of dose limits

• Principle of justification

• Principle of optimisation

• Procedural values

• Progenitor cell

• Programmed cell death

• Projected dose

• Protection strategy

• Protective action

• Protective action guide

• Prudence

• Public exposure

Q

• Qualified expert

• Quality factor, Q(L)

• Quasi-threshold dose

R

• Radiation belt

• Radiation detriment (see Detriment)

• Radiation modifier

• Radiation risk

• Radiation safety officer

• Radiation source

• Radiation weighting factor, w_R

• Radiation worker

• Radioactive dispersion device

• Radioactive source

• Radioactive substance

• Radioactivity

• Radiofrequency ablation

• Radiographer

• Radiological controlled area

• Radiological protection principles

• Radionuclides of natural origin

• Radioresponsiveness

• Radiosensitiser

• Radiosensitivity, cellular

• RAP (see Reference Animal and Plant)

• RBE (see Relative biological effectiveness)

• Reactive oxygen species

• Reasonableness

• Recovery

• Recovery responder

• Recovery (cellular or tissue)

• Reference Animal and Plant

• Reference bioassay function

• Reference biokinetic model

• Reference female (see Reference Individual)

• Reference individual

• Reference level

• Reference male (see Reference Individual)

• Reference parameter value

• Reference Person

• Reference phantom

• Reference worker

• REID (see Lifetime risk estimates)

• Rehabilitation of living conditions

• Relative biological effectiveness

• Relative life lost

• Relative risk

• Relocation

• Remedial action

• Remediation

• Repopulation

• Representative organism (non-human biota)

• Representative person

• Reproductive integrity

• Residual dose

• Respiratory protection

• Response function (see Dose-response function)

• Retrievability

• Reversibility

• Right to know

• Rigidity threshold

• Rigidity

• Ring chromosome

• Risk

• Risk coefficient

• Risk model

• Risk of exposure-induced death (see (see Lifetime risk estimates)

• ROS (see Reactive oxygen species)

• Routine monitoring

• RR (see Relative risk)

S

• S coefficient (radiation weighted) S_W[(r_T←r_s)]

• SAF (see Specific absorbed fraction)

• Safety case

• Safety culture

• Scintigraphy

• SEE (see Specific effective energy]

• Self-help protection

• Senescence

• Severe deterministic injury

• Sievert (Sv)

• SLDR (see Sublethal damage repair)

• Slow repair

• Solar cosmic radiation

• Solar cycle

• Solar particle event

• Solar wind

• Somatic effect

• Source (see Radiation source)

• Source region

• Source term

• Source-related

• South Atlantic anomaly

• Special (non-routine) monitoring

• Specific absorbed fraction

• Specific effective energy

• Spongiosa

• Spontaneous fission

• Stakeholder

• Stenosis

• Stochastic effect

• Storage

• Subcutaneous tissue

• Sublethal damage repair

• Substantial radiation dose level

• Supervised area

• Systemic model

T

• Tachycardia

• Target region

• Target tissue

• Targeted effects

• Telangiectasia

• Thermodynamic diameter

• Thoracic airways

• Threshold dose for tissue reactions

• Threshold levels

• Tissue absorbed dose (see Organ/tissue absorbed dose)

• Thyroid blocking

• Time factor

• Tissue equivalent material

• Tissue reaction

• Tissue weighting factor

• Tolerability

• Track structure

• Transfer compartment

• Transfer of risk

• Transfer rate

• Transforming growth factor

• Transgenerational effect

• Translocation

• Transparency

• Transport of risk (see Transfer of risk)

• Tumour suppressor gene

• Trapped particles

• Types of materials

U

• Unattached fraction

• Unsealed source

• Uptake

• Utilitarian ethics

V

• Value judgement

• Valvular heart disease

• Virtue ethics

• Voxel phantom

W

• Waste disposal

• Wisdom

• w_T (see Tissue weighting factor)

• w_R (see Radiation weighting factor)

X

• X ray

• Xerostomia

Y

Z

...

• α/β value

• α/β ratio (see α/β value)

• γH2AX foci