In this report, the Commission provides guidance for the protection of people living in long-term contaminated areas resulting from either a nuclear accident or a radiation emergency. The report considers the effects of such events on the affected population. This includes the pathways of human exposure, the types of exposed populations, and the characteristics of exposures. Although the focus is on radiation protection considerations, the report also recognises the complexity of post-accident situations, which cannot be managed without addressing all the affected domains of daily life, i.e. environmental, health, economic, social, psychological, cultural, ethical, political, etc. The report explains how the 2007 Recommendations apply to this type of existing exposure situation, including consideration of the justification and optimisation of protection strategies, and the introduction and application of a reference level to drive the optimisation process. The report also considers practical aspects of the implementation of protection strategies, both by authorities and the affected population. It emphasises the effectiveness of directly involving the affected population and local professionals in the management of the situation, and the responsibility of authorities at both national and local levels to create the conditions and provide the means favouring the involvement and empowerment of the population. The role of radiation monitoring, health surveillance, and the management of contaminated foodstuffs and other commodities is described in this perspective. The Annex summarises past experience of long term contaminated areas resulting from radiation emergencies and nuclear accidents, including radiological criteria followed in carrying out remediation measures.

This report considers the evidence relating to cancer risk associated with exposure to low doses of low-LET radiation, and particularly doses below current recommended limits for protection of radiation workers and the general public. It looks at the possibility of establishing a universal threshold dose below which there is no risk of radiation-related cancer. The focus is on evidence regarding linearity of dose response for all cancers considered as a group, but not necessarily individually, at low doses (the so-called linear, no-threshold (LNT) hypothesis). The report concludes that while existence of a low-dose threshold does not seem unlikely for radiation-related cancers, it does not favor the existence of a universal threshold. The LNT hypothesis, combined with an uncertain dose and dose rate effectiveness factor (DDREF) for extrapolation from high doses, remains a prudent basis for radiation protection at low doses and low dose rates.

In the present report, ICRP provides information on radiation doses to the infant due to intakes of radionuclides in maternal milk. As in Publication 88 (ICRP, 2001) on doses to the embryo and fetus following intakes of radionuclides by the mother, intakes by female members of the public and female workers are addressed. Acute and chronic intakes are considered at various times before and during pregnancy as well as during the period of breastfeeding. Dose coefficients per unit intake by the mother (Sv/Bq) are given for the selected radionuclides of the same 31 elements for which age-specific biokinetic models were given in Publications 56, 67, 69, and 71. For these elements, doses were calculated for the most radiologically significant natural or artificial radionuclides that might be released into the environment due to various human activities. Dose coefficients are also given in this report for radionuclides of an additional four elements: sodium, magnesium, phosphorus, and potassium.

The purpose of this Publication is to provide guidance on radiological protection in industries involving NORM. These industries may give rise to multiple hazards and the radiological hazard is not necessarily dominant. The industries are diverse and may involve exposure to people and the environment where protective actions need to be considered. In some cases, there is a potential for significant routine exposure to workers and members of the public if suitable control measures are not considered.

Following the issuance of new radiological protection recommendations in Publication 103 (ICRP, 2007), the Commission released, in Publication 110 (ICRP, 2009), the adult male and female voxel-type reference computational phantoms to be used for the calculation of the reference dose coefficients for both external and internal exposures. While providing more anatomically realistic representations of internal anatomy than the older stylised phantoms, the voxel phantoms have their limitations, mainly due to voxel resolution, especially with respect to small tissue structures (e.g. lens of the eye) and very thin tissue layers (e.g. stem cell layers in the stomach wall mucosa and intestinal epithelium). This report describes the construction of the adult mesh-type reference computational phantoms (MRCPs) that are the modelling counterparts of the Publication 110 voxel-type reference computational phantoms. The MRCPs include all source and target regions needed for estimating effective dose, even the m-thick target regions in the respiratory and alimentary tract, skin, and urinary bladder, assimilating the supplemental stylised models. The MRCPs can be directly implemented into Monte Carlo particle transport codes for dose calculations, i.e. without voxelisation, fully maintaining the advantages of the mesh geometry.

This report describes the development and intended use of a series of ten computational phantoms representing the reference male and female at newborn, 1-year-old, 5-year-old, 10-year-old, and 15-year-old as defined in Publication 89. These phantoms have been formally adopted by the ICRP for use within ICRP Committee 2 in the development of age-dependent dose coefficients following the 2007 Recommendations. They are presented in this report in the very same voxelised structures and tissue ID numbers as given in Publication 110 for the adult reference computational phantoms. These paediatric phantoms have been used by Task Group 90 of ICRP Committee 2 in the development of age-dependent dose coefficients representing external exposures to contaminated air, water, and soil. They have also been used by Task Group 96 of ICRP Committee 2 in the development of age-dependent specific absorbed fractions for internally emitted photons, electrons, alpha particles, and neutrons, in a manner similar to the adult SAF (Specific Absorbed Fraction) values given in Publication 133.

For its 4th International Symposium on the System of Radiological Protection, ICRP joined forces with the 2nd European Radiological Protection Research Week (ERPW), to collaborate closely with the five European research platforms: ALLIANCE, EURADOS, EURAMED, MELODI, and NERIS. ICRP-ERPW 2017 attracted more than 500 participants from 42 countries.

This report provides a review of stem cells/progenitor cells and their responses to ionising radiation in relation to issues relevant to stochastic effects of radiation which form a major part of the ICRP system of radiological protection. Current information on stem cell characteristics, maintenance and renewal, evolution with age, location in stem cell "niches", radiosensitivity to acute and protracted exposures, is presented in a series of substantial reviews as Annexes concerning haematopoietic tissue, mammary gland, thyroid, digestive tract, lung, skin and bone. This foundation of knowledge of stem cells is used in the main text of the report to provide a biological insight to issues such as the linear-no-threshold (LNT) model, cancer risk among tissues, dose-rate effects and changes in the risk of radiation carcinogenesis by age at exposure and attained age.

This report provides a compendium of current information relating to radiation dose to patients, including biokinetic models, biokinetic data, dose coefficients for organ and tissue absorbed doses, and effective dose for major radiopharmaceuticals based on ICRP radiation protection guidance. These data were compiled from ICRP Publications 53, 80, and 106 and related amendments and corrections. This report also includes new information for 82Rb-chloride, iodide (123I, 124I, 125I, and 131I) and 123I labelled 2ss-carbomethoxy 3ss-(4-iodophenyl)-N-(3-fluoropropyl) nortropane (FPCIT). The data presented in this report are intended for diagnostic nuclear medicine and not for therapeutic applications.

This publication aims to provide guidance on radiological protection in the new technology of cone beam computed tomography (CBCT). CBCT is now used widely by specialists who have little or no training in radiological protection. This publication provides recommendations on radiation dose management directed at different stakeholders, and covers principles of radiological protection, training, and quality assurance aspects. As with previous ICRP publications, the Commission hopes that imaging professionals, medical physicists, and manufacturers will use the guidelines and recommendations provided in this publication for implementation of the Commission's principle of optimisation of protection of patients and medical workers, with the objective of keeping exposures as low as reasonably achievable, taking into account economic and societal factors, and consistent with achieving the necessary medical outcomes.

The International Commission on Radiological Protection (ICRP) has developed and systematically updated the system of radiological protection, which now recommends optimisation of protection measures within or guided by appropriate restrictions, such as dose constraints or reference levels, in all circumstances. This applies to all exposure situations (planned, emergency and existing) and all categories of exposure (occupational, medical, and public). Optimisation of protection is intended to reduce exposures to levels that are as low as reasonably achievable, economic and societal considerations being taken into account, and to manage medical exposures commensurate with the medical purpose.

In this report the Commission describes its framework for protection of the environment and how it should be applied within the Commission's system of protection. The report expands upon its objectives in relation to protection of the environment and explains the different types of exposure situations to which its recommendations apply. Further recommendations are made with regard to how the Commission's recommendations can be implemented to satisfy different forms of environmental protection objectives and additional information is also given with regard to, in particular, communication with other interested parties and stakeholders. Issues that may arise in relation to compliance are also discussed and a final chapter discusses the overall implications of the Commission's work in this area to date. Appendices 1 and 2 provide some numerical information relating to the Reference Animals and Plants. An Annex to this report considers some of existing types of environmental protection legislation currently in place in relation to large industrial sites and practices, and the various ways in which wildlife are protected from various threats arising from such sites.

Radiopharmaceuticals are increasingly used for the treatment of various cancers with novel radionuclides, compounds, tracer molecules, and administration techniques. The goal of radiation therapy, including therapy with radiopharmaceuticals, is to optimise the relationship between tumour control probability and potential complications in normal organs and tissues. This report provides an overview of therapy procedures and a framework for calculating radiation doses for various treatment approaches.

This report provides the technical basis for SAFs relevant to internalised radionuclide activity in the organs of the reference adult male and reference adult female as defined in Publications 89 and 110. SAFs are given for uniform distributions of monoenergetic photons, electrons, alpha particles, and fission-spectrum neutrons over a range of relevant energies. Electron SAFs include both their collision and radiative components of energy deposition. SAF data are matched to source and target organs of the biokinetic models of the OIR publication series. The document further outlines the computational methodology and nomenclature for assessment of internal dose in a manner consistent with that used for nuclear medicine applications. Numerical data for particle specific and energy dependent SAFs are given in electronic format for numerical coupling to the respiratory tract, alimentary tract, and systemic biokinetic models of the OIR publication series.

In this publication, the International Commission on Radiological Protection (ICRP) provides updated guidance on radiological protection from cosmic radiation in aviation, taking into account the current ICRP system of radiological protection, the latest available data on exposures in aviation, and experience gained worldwide in the management of exposures in aviation. The publication describes the origins of cosmic radiation, how it exposes passengers and aircraft crew, the basic radiological protection principles that apply to this existing exposure situation, and the available protective actions. For implementation of the optimisation principle, the Commission recommends a graded approach proportionate to the level of exposure that may be received by individuals. The objective is to keep the exposure of the most exposed individuals to a reasonable level. The Commission also recommends that information be disseminated to raise awareness about cosmic radiation, and to support informed decisions among concerned stakeholders.

The effect of ionising radiation is influenced by the dose, the dose rate, and the quality of the radiation. Before 1990, dose-equivalent quantities were defined in terms of a quality factor, Q(L), that was applied to the absorbed dose at a point in order to take into account the differences in the effects of different types of radiation. In its 1990 recommendations, the ICRP introduced a modified concept. For radiological protection purposes, the absorbed dose is averaged over an organ or tissue, T, and this absorbed average dose is weighted for the radiation quality in terms of the radiation weighting factor, wR, for the type and energy of radiation incident on the body. The resulted weighted dose is designated as the organ- or tissue-equivalent dose, HT. The sum of the organ-equivalent doses weighted by the ICRP organ-weighting factors, wT, is termed the effective dose, E. Measurements can be performed in terms of the operational quantities, ambient dose equivalent, and personal dose equivalent. These quantities continue to be defined in terms of the absorbed dose at the reference pointed weighted by Q(L).
The values for wR and Q(L) in the 1990 recommendations were based on a review of the biological and other information available, but the underlying relative biological effectiveness (RBE) values and the choice of wR values were not elaborated in detail. Since 1990, there have bneen substantial developments in biological and dosimetric knowledge that justify a re-appraisal of wR values and how they may be derived.
This re-appraisal is the principal objective of the present report. The report discusses in some detail the values of RBE with regard to stochastic effects, whichare central to the selection of wR and Q(L). Those factors and the dose-equivalent quantities are restricted to the dose range of interest to radiation protection, i.e. to the general magnitude of the dose limits. In special circumstances where one deals with higher doses that can cause deterministic effects, the relevant RBE values are applied to obtain a weighted dose. The question of RBE values for deterministic effects and how they should be used is also treated in the report, but it is an issue that will demand further investigations.
This report is one of a set of documents being developed by ICRP Committees in order to advice the ICRP on the formulation of its next Recommendations for Radiological Protection. Thus, while the report suggests some future modifications, thewR values given in the 1990 recommendations are still valid at this time. The report provides a scientific background and suggests how the ICRP might proceed with the derivation of wR values ahead of its forthcoming recommendations.