Annals of the ICRP
14 total works
In Publication 103, the Commission included a section on the protection of the environment, and indicated that it would be further developing its approach to this difficult subject by way of a set of Reference Animals and Plants (RAPs) as the basis for relating exposure to dose, and dose to radiation effects, for different types of animals and plants.
Subsequently, a set of 12 RAPs has been described in some detail, particularly with regard to estimation of the doses received by them, at a whole-body level, in relation to internal and external radionuclide concentrations; and what is known about the effects of radiation on such types of animals and plants. A set of dose conversion factors for all of the RAPs has been derived, and the resultant dose rates can be compared with evaluations of the effects of dose rates using derived consideration reference levels (DCRLs). Each DCRL constitutes a band of dose rates for each RAP within which there is likely to be some chance of the occurrence of deleterious effects. Site-specific data on Representative Organisms (i.e. organisms of specific interest for an assessment) can then be compared with such values and used as a basis for decision making.
Subsequently, a set of 12 RAPs has been described in some detail, particularly with regard to estimation of the doses received by them, at a whole-body level, in relation to internal and external radionuclide concentrations; and what is known about the effects of radiation on such types of animals and plants. A set of dose conversion factors for all of the RAPs has been derived, and the resultant dose rates can be compared with evaluations of the effects of dose rates using derived consideration reference levels (DCRLs). Each DCRL constitutes a band of dose rates for each RAP within which there is likely to be some chance of the occurrence of deleterious effects. Site-specific data on Representative Organisms (i.e. organisms of specific interest for an assessment) can then be compared with such values and used as a basis for decision making.
The Commission’s 1990 recommendations on radiation protection standards in ICRP Publication 60 were developed to take into account new biological information related to the detriment associated with radiation exposures and supersede the earlier recommendations in ICRP Publication 26. In order to permit immediate application of these new recommendations, revised values of the Annual Limits on Intake (ALIs) based on the methodology and biokinetic information and incorporating the new dose limits and tissue weighting factors, wT were issued as ICRP Publication 61. Since issuing ICRP Publication 61, ICRP has published a revised kinetic and dosimetric model of the respiratory tract. The main aim of the present report is to give values of dose coefficients for workers using this new model.
This publication is intended to review, update and extend the information on the metabolism of plutonium, neptunium and the trivalent actinides, previously reviewed in ICRP Publication 19, with special reference to the absorption from the gastro-intestinal tract, the retention times in liver and skeleton, the influence of bone remodelling on the microdistribution within the skeleton and the relation of actinide metabolism to that of other radionuclides. This report is intended to complement, rather than replace, the original report and it has not been thought appropriate to reproduce all the extensive data presented in ICRP Publication 19. The new report follows the general patter of the first one, beginning with a short overview of some salient features of the chemistry of the actinides in mammalian systems and then reviewing the behaviour of the elements following entry by inhalation, by ingestion, or through the skin. The penultimate chapter reviews the retention of plutonium and the actinides in liver, bone, gonads and the other organs of the human body.
Ingestion Dose Coefficients The present report on age dependent dose coefficients to members of the public follows ICRP Publications 56 and 67. The following elements are covered: iron, selenium, antimony, thorium and uranium. This report gives parameters for the tissue distribution and retention of these elements together with data on urinary and faecal excretion. Dose coefficients have been calculated for radioisotopes of these elements which are expected to be released into the environment as a result of human activities and are considered to be of significance for environmental radiation protection purposes. The generic model structure for plutonium, americium and neptunium given in ICRP Publication 67 has been applied to thorium; the generic model structure for the alkaline earths given in ICRP Publication 67 has been applied to uranium. Where no clear evidence on age dependence of organ distribution and retention appeared to be available, the biokinetic data for adults were adopted for infants and children. This assumption was made in ICRP Publications 56 and 67, and is usually expected to lead to an overestimate of the dose coefficient. If no relevant biokinetic data were found for humans, appropriate data were based on animal experiments as far as possible.
ICRP Publication 76 develops the principles outlined in ICRP Publication 60 and elaborates on the concepts in ICRP Publication 64 concerning protection from potential exposure. It deals with such potential exposure primarily affecting individuals who are also subject to exposures in normal practices, either occupationally, as members of the public, or as patients. Thus, in simple terms, it deals with `common smaller accidents’. Such cases are conceptually less complicated than potential exposure affecting large numbers of people, such as nuclear disasters, or potential exposure that could occur far into the future, for instance from deep repositories for waste disposal. However, the problems discussed in the report need to be dealt with more frequently in practical situations and not least in optimisation. The report contains much `hands-on’ practical example material, and should be useful in all workplaces, where it can help bridge any gap between safety and protection.
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.
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 dose average 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 resulting 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 point weighted by Q(L).
In March 1987 the International Commission on Radiological Protection established a Task Group of Committee 2 "to evaluate dose per unit intake for members of the public". In this, the second of two reports given by the Task Group, ingestion dose coefficients are given for isotopes of sulphur, cobalt, nickel, zinc, molybdenum, technetium, silver, tellurium and polonium using the new tissue weighting factors (wT) given by the Commission in its 1990 Recommendations. Revised ingestion dose coefficients are also included for the radioisotopes given in Part 1 using the new wT values. In addition, ingestion dose coefficients are given for further radioisotopes. A generic model for the biokinetics of lead and the alkaline earths strontium, barium and radium has been introduced for calculating ingestion dose coefficients for radioisotopes of these elements. This model has been applied to the recalculation of the ingestion dose coefficients for Sr-90, the only strontium isotope considered in Part 1.
The ICRP has now given new wT values for the urinary bladder and colon, and new information has become available on the biokinetics of plutonium, americium and neptunium in humans. As a result the Task Group considered it appropriate to revise the biokinetic models for these elements given in Part 1.
The ICRP has now given new wT values for the urinary bladder and colon, and new information has become available on the biokinetics of plutonium, americium and neptunium in humans. As a result the Task Group considered it appropriate to revise the biokinetic models for these elements given in Part 1.
The proposed framework is designed to harmonise with the ICRP’s approach to the protection of human beings, but does not intend to set regulatory standards. Instead, the proposed framework is intended to be a practical tool to provide high-level advice and guidance for regulators and operators. An agreed set of quantities and units, a set of reference dose models, reference dose-per-unit-intake (or unit exposure), and reference fauna and flora are required to serve as a basis for the more fundamental understanding and interpretation of the relationships between exposure and dose and between dose and certain categories of effect, for a few, clearly defined types of animals and plants. As a first step, a small set of reference fauna and flora with supporting databases will be developed by the ICRP. Others can then develop more area- and situation-specific approaches to assess and manage risks to non-human species.
This supplement gives relevant dosimetric data for radionuclides considered in ICRP Publication Number 30, Part 2.
ICRP Publication 81 deals with the radiological protection of members of the public following the disposal of long-lived solid radioactive waste using the ‘concentrate and retain’ strategy. It covers options including shallow land burial and deep geological disposal. Its recommendations apply to new disposal facilities. The report supplements, updates, and clarifies the material in ICRP Publication 46 from 1986, taking into account the most recent general recommendations of ICRP in Publication 60 and the general ICRP policy for disposal of all types of radioactive waste as described in Publication 77. It addresses the main protection issue: exposure that may or may not occur in the far future, and regards constrained optimisation as the central approach to evaluating radiological acceptability of a waste disposal system. In this context, optimisation is a judgmental, essentially qualitative process. Two categories of exposure situation are considered: natural processes and human intrusion.
ICRP Publication 75 reports comprehensively on the principles for the protection of workers from ionising radiation. It develops guidance on the implementation of the principles in the 1990 Recommendations of the ICRP (ICRP Publication 60), including the concepts of constraint and reference levels. The report discusses the management of occupational exposure in normal and emergency situations, in Industrial and medical contexts, and with respect to natural sources of radiation, including radon, at work. Health surveillance of workers and the management of overexposed individuals are considered. This report updates ICRP Publication 28 with respect to principles and procedures for handling emergency and accidental exposures of workers, and, by laying out the principles of monitoring for external radiation, completely replaces ICRP Publication 35. Monitoring for radionuclide contamination is also discussed. The report should also be of interest to a wide readership including all those responsible for occupational health, at operational and managerial levels, as well as regulatory bodies and professional organisations.
This publication reviews what is known about the effects of radiation upon such biotic types (or of similar organisms, where more precise data are lacking) with regard to the effects of mortality, morbidity, reduced reproductive success, and chromosomal damage. Drawing on this information, the report derives a set of derived consideration reference levels for each biotic type in order to help optimise the level of effort that might be expended on its environmental protection, or that of similar types of organisms, and thus serve as points of reference in any wider consideration of what authorities may wish to do under different exposure situations. The various factors that should be taken into account when considering what to do if the derived consideration reference levels are likely to be attained are also discussed. Some broader background information on the types of animals and plants used is also given. Additional information is provided on advice with regard to extrapolating and interpolating the limited set of dosimetric models to other shapes and sizes of animals and plants.
Despite the increase in data and the understanding of both deterministic effects and cancer induction in the skin in recent years, many questions that are important for risk estimation remain. This report, adopted by the ICRP in November 1991, is the work of a Task Group set up to consider the biological basis for dose limitation in the skin. The Task Group reviewed available dose-effect data for cancer induction and deterministic effects in the skin to estimate for these effects; it reviewed evidence concerning which cells are at risk, to determine at what depth dose measurements should be made, and re-examined dosimetry considerations and weighting factors for skin, with reference to the effects of ‘hot particles’ and ultraviolet radiation. The information collated in this report was used by the Commission to set dose limits and the weighting factor for skin in the 1990 Recommendations of the ICRP.