Quotes from Publications on the System of Radiological Protection

Module One: The System of Radiological Protection

ICRP Publication 103 paragraph 44

The Commission’s system of radiological protection applies to all radiation exposures from any source, regardless of its size and origin. The term radiation is used to mean ionising radiation. The Commission has been using the term radiation exposure (or exposure in short) in a generic sense to mean the process of being exposed to radiation or radionuclides, the significance of exposure being determined by the resulting radiation dose ... The term ‘source’ is used to indicate the cause of an exposure, and not necessarily a physical source of radiation ...

ICRP Publication 103 paragraph 45

The Commission has aimed to make its Recommendations applicable as widely and as consistently as possible. In particular, the Commission’s Recommendations cover exposures to both natural and man-made sources. The Recommendations can apply in their entirety only to situations in which either the source of exposure or the pathways leading to the doses received by individuals can be controlled by some reasonable means ...

ICRP Publication 103 paragraph 27

... The Recommendations are based on scientific knowledge and on expert judgement. Scientific data, such as those concerning health risks attributable to radiation exposure, are a necessary prerequisite, but societal and economic aspects of protection have also to be considered. All of those concerned with radiological protection have to make value judgements about the relative importance of different kinds of risk and about the balancing of risks and benefits. In this, radiological protection is not different from other fields concerned with the control of hazards ...

Module One: Objectives of Radiological Protection

ICRP Publication 103 paragraph 29

The Commission’s system of radiological protection aims primarily to protect human health. Its health objectives are relatively straightforward: to manage and control exposures to ionising radiation so that deterministic effects are prevented, and the risks of stochastic effects are reduced to the extent reasonably achievable.

Types of effects: ICRP Publication 103 paragraph 5

Most adverse health effects of radiation exposure may be grouped in two general categories:

• deterministic effects (harmful tissue reactions) due in large part to the killing/ malfunction of cells following high doses; and
• stochastic effects, i.e., cancer and heritable effects involving either cancer development in exposed individuals owing to mutation of somatic cells or heritable disease in their offspring owing to mutation of reproductive (germ) cells.

ICRP Publication 103 paragraph 30

... The Commission’s aim is now that of preventing or reducing the frequency of deleterious radiation effects to a level where they would have a negligible impact on the maintenance of biological diversity, the conservation of species, or the health and status of natural habitats, communities and ecosystems. In achieving this aim, however, the Commission recognises that exposure to radiation is but one factor to consider, and is often likely to be a minor one ...

ICRP Publication 103 paragraphs 7 and 8

... The biological endpoints of most relevance are therefore those that could lead to changes in population size or structure. Nevertheless, radiation affects individuals, and most available data on the effects of radiation relate to individuals rather than populations.

The biological endpoints of interest to individuals that could have a consequence at a population level are those of:

• early mortality (leading to changes in age distribution, death rate, and population density);
• some forms of morbidity (that could reduce ‘fitness’ of the individuals, making it more difficult for them to survive in a natural environment);
• impairment of reproductive capacity by either reduced fertility or fecundity (affecting birth rate, age distribution, number, and density); and
• induction of chromosomal damage.

Module One: Fundamental Principles of Radiological Protection

ICRP Publication 103 paragraph 203

The principle of justification: Any decision that alters the radiation exposure situation should do more good than harm.

This means that, by introducing a new radiation source, by reducing existing exposure, or by reducing the risk of potential exposure, one should achieve sufficient individual or societal benefit to offset the detriment it causes.

ICRP Publication 103 paragraph 205

The Commission recommends that, when activities involving an increased or decreased level of radiation exposure, or a risk of potential exposure, are being considered, the expected change in radiation detriment should be explicitly included in the decision-making process. The consequences to be considered are not confined to those associated with the radiation – they include other risks and the costs and benefits of the activity. Sometimes, the radiation detriment will be a small part of the total. Justification thus goes far beyond the scope of radiological protection. It is for these reasons that the Commission only recommends that justification require that the net benefit be positive. To search for the best of all the available alternatives is a task beyond the responsibility of radiological protection authorities.

ICRP Publication 103 paragraph 203

The principle of optimisation of protection: The likelihood of incurring exposures, the number of people exposed, and the magnitude of their individual doses should all be kept as low as reasonably achievable, taking into account economic and societal factors.

This means that the level of protection should be the best under the prevailing circumstances, maximising the margin of benefit over harm. In order to avoid severely inequitable outcomes of this optimisation procedure, there should be restrictions on the doses or risks to individuals from a particular source (dose or risk constraints and reference levels).

ICRP Publication 103 paragraph 211

The process of optimisation of protection is intended for application to those situations that have been deemed to be justified. The principle of optimisation of protection, with restriction on the magnitude of individual dose or risk, is central to the system of protection and applies to all three exposure situations: planned exposure situations, emergency exposure situations, and existing exposure situations.

ICRP Publication 103 paragraph 212

The principle of optimisation is defined by the Commission as the source related process to keep the likelihood of incurring exposures (where these are not certain to be received), the number of people exposed, and the magnitude of individual doses as low as reasonably achievable, taking economic and societal factors into account.

ICRP Publication 103 paragraph 203

The principle of application of dose limits: The total dose to any individual from regulated sources in planned exposure situations other than medical exposure of patients should not exceed the appropriate limits recommended by the Commission.

ICRP Publication 103 paragraph 204

Regulatory dose limits are determined by the regulatory authority, taking account of international recommendations, and apply to workers and to members of the public in planned exposure situations.

ICRP Publication 103 paragraph 243

Dose limits apply only in planned exposure situations but not to medical exposures of patients ... Within a category of exposure, occupational or public, dose limits apply to the sum of exposures from sources related to practices that are already justified.