ICRP与非人类物种辐射防护

迄今为止,ICRP还没有发表过关于如何评价和管理非人类物种辐射效应的建议。现已经决定建立评价非人类物种辐射效应的体系,以填补辐射防护概念上的空白。拟建立的体系不是为了制定审管标准,而是为了提供指导,从而有助于审管部门和运营部门证实自己遵守了现行的法律。ICRP将建立一套参考动植物及相关数据库,以便作为从根本上更多地认识和解释照射和剂量的关系、剂量和某些类型的效应关系的基础。这个概念类似于人类辐射防护所用的参考人概念,目的是作为计算和决策的依据。委员会已经设立了一个新的任务组,继续工作,以确定感兴趣的效应终点、ICRP要用的参考生物类型,以及一套用以评价和管理非人类物种辐射照射的参考剂量模型。     

Prevention of high-dose-rate brachytherapy accidents. ICRP Publication 97

High-dose-rate brachytherapy is a rapidly growing technique (HDR) that has been replacing low-dose-rate (LDR) procedures over the last few years in both industrialised and developing countries. It is estimated that about 500,000 procedures (administration of treatment) are performed by HDR units annually. LDR equipment has been discontinued by many manufacturers over the last few years, leaving HDR brachytherapy as the major alternative. HDR brachytherapy techniques deliver a very high dose, of the order of 1.6-5.0 Gy/min, so mistakes can lead to under- or overdosage with the potential for clinical adverse effects. More than 500 HDR accidents (including one death) have been reported along the entire chain of procedures from source packing to delivery of dose. Human error has been the prime cause of radiation events. In the present report, the International Commission on Radiological Protection concludes that many accidents could have been prevented if staff had had functional monitoring equipment and paid attention to the results. Since iridium has relatively short half-life, the HDR sources need to be replaced approximately every 4 months. Over 10,000 HDR sources are transported annually, with the resultant potential for accidents; therefore, appropriate procedures and regulations must be observed. A number of specific recommendations on procedures and equipment are given in this report. The need for an emergency plan and for practising emergency procedures is stressed. The possibility of loss or theft of sources must be kept in mind. A collaborating team of specifically trained personnel following quality assurance (QA) procedures is necessary to prevent accidents. Maintenance is indispensable component of QA; external audits of procedures re-enforce good and safe practice, and identify potential causes of accidents. QA should include peer review of cases. Accidents and incidents should be reported and the lessons learned should be shared with other users to prevent similar mistakes.     

Human alimentary tract model for radiological protection. ICRP Publication 100. A report of The International Commission on Radiological Protection

In this report, the ICRP provides a new biokinetic and dosimetric model of the human alimentary tract to replace the Publication 30 (ICRP, 1979) model. The new human alimentary tract model (HATM) will be used together with the human respiratory tract model (HRTM; ICRP, 1994a,b) in future ICRP publications on doses from ingested and inhaled radionuclides. The HATM is applicable to all situations of radionuclide intake by children and adults. It provides age-dependent parameter values for the dimensions of the alimentary tract regions, and associated transit times for the movement of materials through these regions. For adults, gender-dependent parameter values are given for dimensions and transit times. The default assumption is that radionuclide absorption takes place in the small intestine, but the model allows for absorption in other regions and for retention in or on tissues within the alimentary tract when information is available. Doses are calculated to target cells for cancer induction in the oral cavity, oesophagus, stomach, small intestine, and colon. This report provides reviews of information on the transit of materials through the alimentary tract and on radionuclide retention and absorption. It considers data on health effects, principally in order to specify the target cells for cancer induction within the mucosal lining of the tract and to justify approaches taken to dose averaging within regions. Comparisons are made between doses calculated using the HATM and the Publication 30 model for examples of radionuclide ingestion for which absorption is assumed to occur in the small intestine alone. Examples are also given of the effects on doses of considering absorption from other regions and the effect of possible retention in the alimentary tract. This report also considers uncertainties in model assumptions and their effect on doses, including alimentary tract dimensions, transit times, radionuclide absorption values, and the location of targets for cancer induction.     

ICRP Publication 114. Environmental protection: transfer parameters for reference animals and plants

In Publication 103 (ICRP, 2007), 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 (ICRP, 2008), 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. It is intended that the Commission's approach to protection of the environment be applied to all exposure situations. In some situations, the relevant radionuclide concentrations can be measured directly, but this is not always possible or feasible. In such cases, modelling techniques are used to estimate the radionuclide concentrations. This report is an initial step in addressing the needs of such modelling techniques. After briefly reviewing the basic factors relating to the accumulation of radionuclides by different types of biota, in different habitats, and at different stages in the life cycle, this report focuses on the approaches used to model the transfer of radionuclides through the environment. It concludes that equilibrium concentration ratios (CRs) are most commonly used to model such transfers, and that they currently offer the most comprehensive data coverage. The report also reviews the methods used to derive CRs, and describes a means of summarising statistical information from empirical data sets. Emphasis has been placed on using data from field studies, although some data from laboratory experiments have been included for some RAPs. There are, inevitably, many data gaps for each RAP, and other data have been used to help fill these gaps. CRs specific to each RAP were extracted from a larger database, structured in terms of generic wildlife groups. In cases where data were lacking, values from taxonomically-related organisms were used to derive suitable surrogate values. The full set of rules which have been applied for filling gaps in RAP-specific CRs is described. Statistical summaries of the data sets are provided, and CR values for 39 elements and 12 RAP combinations are given. The data coverage, reliance on derived values, and applicability of the CR approach for each of the RAPs is discussed. Finally, some consideration is given to approaches where RAPs and their life stages could be measured for the elements of interest under more rigorously controlled conditions to help fill the current data gaps.     

Radiation safety aspects of brachytherapy for prostate cancer using permanently implanted sources. A report of ICRP Publication 98

The use of permanent radioactive implants (125I or 103Pd seeds) to treat selected localised prostate cancer patients has been increasing rapidly all over the world for the last 15 years. It is estimated that more than 50,000 patients are treated this way every year in the world, and this number is anticipated to increase in the near future. Although no accidents or adverse effects involving medical staff and/or members of the patient's family have been reported to date, this brachytherapy technique raises a number of radiation safety issues that need specific recommendations from the ICRP. All data concerning the dose received by people approaching patients after implantation have been reviewed. Those doses have been either been measured directly or calculated. The available data show that, in the vast majority of cases, the dose to comforters and carers remains well below the recommended limit of 1 mSv/year. Only the (rare) case where the patient's partner is pregnant at the time of implantation may need specific precautions. Expulsion of sources through urine, semen, or the gastro-intestinal tract is rare. Specific recommendations should be given to patients to allow them to deal adequately with this event. Of note, due to the low activity of an isolated seed and its low photon energy, no incident/accident linked to seed loss has ever been recorded. When performed in the first few months after implantation, cremation of bodies (frequent in some countries) raises several issues related to: (1) the activity that remains in the patient's ashes; and (2) the airborne dose, potentially inhaled by crematorium staff or members of the public. Review of available data shows that cremation can be allowed if 12 months have elapsed since implantation with 125I (3 months for 103Pd). If the patient dies before this delay has elapsed, specific measures must be undertaken. Specific recommendations have to be given to the patient to warn his surgeon in case of subsequent pelvic or abdominal surgery. A 'wallet card' with all relevant information about the implant is useful. In most cases, brachytherapy does make the patient infertile. However, although the therapy-related modifications of the semen reduce fertility, patients must be aware of the possibility of fathering children after such a permanent implantation, with a limited risk of genetic effects for the child. Patients with permanent implants must be aware of the possibility of triggering certain types of security radiation monitors. The 'wallet card' including the main information about the implant (see above) may prove to be helpful in such a case. Considering the available experience after brachytherapy and external irradiation of prostate cancer, the risk of radio-induced secondary tumours appears to be extremely low. The demonstrated benefit of brachytherapy clearly outweighs, by far, the very limited (mainly theoretical)increase in the radiation-induced cancer risk.     

ICRP Publication 115. Lung cancer risk from radon and progeny and statement on radon

Recent epidemiological studies of the association between lung cancer and exposure to radon and its decay products are reviewed. Particular emphasis is given to pooled case-control studies of residential exposures, and to cohorts of underground miners exposed to relatively low levels of radon. The residential and miner epidemiological studies provide consistent estimates of the risk of lung cancer, with significant associations observed at average annual concentrations of approximately 200 Bq/m3 and cumulative occupational levels of approximately 50 working level months (WLM), respectively. Based on recent results from combined analyses of epidemiological studies of miners, a lifetime excess absolute risk of 5 × 10?? per WLM [14 × 10?? per (mJh/m3)] should now be used as the nominal probability coefficient for radon- and radon-progeny-induced lung cancer, replacing the previous Publication 65 (ICRP, 1993) value of 2.8 × 10?? per WLM [8 × 10?? per (mJh/m3)]. Current knowledge of radon-associated risks for organs other than the lungs does not justify the selection of a detriment coefficient different from the fatality coefficient for radon-induced lung cancer. Publication 65 (ICRP, 2003) recommended that doses from radon and its progeny should be calculated using a dose conversion convention based on epidemiological data. It is now concluded that radon and its progeny should be treated in the same way as other radionuclides within the ICRP system of protection; that is, doses from radon and its progeny should be calculated using ICRP biokinetic and dosimetric models. ICRP will provide dose coefficients per unit exposure to radon and its progeny for different reference conditions of domestic and occupational exposure, with specified equilibrium factors and aerosol characteristics.     

Radiation protection recommendations as applied to the disposal of long-lived solid radioactive waste. ICRP Publication 81

The present publication 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. The recommendations made in this report apply to new disposal facilities.The main protection issue concerns exposure that may or may not occur in the far future, i.e. a situation of potential exposure. Constrained optimisation is the central approach to evaluating the radiological acceptability of a waste disposal system. In this context optimisation of protection is a judgmental process with social and economic factors being taken into account and should be conducted in a structured essentially qualitative way.Two broad categories of exposure situations have to be considered: natural processes and human intrusion. Application of the radiological protection criteria to these two categories of exposure situations is different.In the first case, assessed doses or risks arising from natural processes should be compared with a constraint of no more than about 0.3 mSv per year or its risk equivalent of around 10(-5) per year. With regard to human intrusion, understood here as inadvertent human intrusion, the consequences from one or more plausible stylised scenarios should be considered in order to evaluate the resilience of the repository to such events. The Commission considers that in circumstances where human intrusion could lead to doses to those living around the site sufficiently high that intervention on current criteria would almost always be justified, reasonable efforts should be made at the repository development stage to reduce the probability of human intrusion or to limit its consequences. In this respect, the Commission has previously advised that an existing(1) annual dose of around 10 mSv per year may be used as a generic reference level below which intervention is not likely to be justifiable. Conversely, an existing(1) annual dose of around 100 mSv per year may be used as a generic reference level above which intervention should be considered almost always justifiable. Similar considerations apply in situations where the thresholds for deterministic effects in relevant organs are exceeded.The conclusion of the report is that in the Commission's view, provided reasonable measures have been taken both to satisfy the constraint for natural processes and to reduce the probability or the consequences of inadvertent human intrusion, and technical and managerial principles have been followed, then radiological protection requirements can be considered to have been complied with.     

Guide for the practical application of the ICRP Human Respiratory Tract Model. A report of ICRP supporting guidance 3: approved by ICRP committee 2 in October 2000

The ICRP Publication 66 Human Respiratory Tract Model for Radiological Protection (HRTM) has been applied to calculate dose coefficients (doses per unit intake) and bioassay functions in ICRP Publications 68, 71, 72 and 78. For these purposes, ICRP assigned numerical values to a range of model parameters, such as the size of the inhaled particles and the breathing rate of the subjects. These are known as 'default' or 'reference' values, and were chosen to be typical, representative values. In any particular situation the actual values of many parameters can be considerably different from the reference values. Usually, doses from intakes of radionuclides are low compared with the relevant limit or constraint, and the resulting difference is unimportant. There are, however, circumstances where more reliable assessments of intake and dose are desirable. This Guidance Document therefore gives advice on applying specific information within the framework of the HRTM for assessing occupational and environmental exposures and for interpreting bioassay data. Chapters on each aspect of the model (morphometry, physiology, deposition, clearance, gases and vapours, dosimetry) provide: A summary of how the HRTM treats that topic;Information on the reference values of relevant parameters;Guidance on choosing between default values;Information on how doses and bioassay quantities (lung retention, urine, and faecal excretion) vary with the values of selected parameters, giving guidance on the importance of obtaining specific information;Simple examples of the use of specific information relating to the topic.Annexes give additional information for those directly involved in applying the HRTM to specific situations, including guidance on obtaining parameter values. A brief overview is given of the deposition, characterisation, and sampling of aerosols, with references to further information, as there are relevant text books already available. Issues specific to radioactive aerosols, such as low particle number concentrations for high specific activity materials are, however, addressed. Guidance on obtaining information about absorption of inhaled radionuclides into blood is given in greater detail, because this is a topic on which ICRP has traditionally given guidance, and because a compilation of such information is not readily available elsewhere. Several detailed examples are also provided. One involves assessment of an individual's intake and committed dose from comprehensive bioassay monitoring data. The others deal with the derivation of HRTM absorption parameter values from experimental data, and their application, with additional information on e.g. size distribution, to calculate dose coefficients and interpret bioassay data.     

Assessing dose of the representative person for the purpose of radiation protection of the public. ICRP publication 101. Approved by the Commission in September 2005

The Commission intended that its revised recommendations should be based on a simple, but widely applicable, system of protection that would clarify its objectives and provide a basis for the more formal systems needed by operating managers and regulators. The recommendations would establish quantified constraints, or limits, on individual dose from specified sources. These dose constraints apply to actual or representative people who encounter occupational, medical, and public exposures. This report updates the previous guidance for estimating dose to the public. Dose to the public cannot be measured directly and, in some cases, it cannot be measured at all. Therefore, for the purpose of protection of the public, it is necessary to characterise an individual, either hypothetical or specific, whose dose can be used for determining compliance with the relevant dose constraint. This individual is defined as the 'representative person'. The Commission's goal of protection of the public is achieved if the relevant dose constraint for this individual for a single source is met and radiological protection is optimised. This report explains the process of estimating annual dose and recognises that a number of different methods are available for this purpose. These methods range from deterministic calculations to more complex probabilistic techniques. In addition, a mixture of these techniques may be applied. In selecting characteristics of the representative person, three important concepts should be borne in mind: reasonableness, sustainability, and homogeneity. Each concept is explained and examples are provided to illustrate their roles. Doses to the public are prospective (may occur in the future) or retrospective (occurred in the past). Prospective doses are for hypothetical individuals who may or may not exist in the future, while retrospective doses are generally calculated for specific individuals. The Commission recognises that the level of detail afforded by its provision of dose coefficients for six age categories is not necessary in making prospective assessments of dose, given the inherent uncertainties usually associated with estimating dose to the public and with identification of the representative person. It now recommends the use of three age categories for estimating annual dose to the representative person for prospective assessments. These categories are 0-5 years (infant), 6-15 years (child), and 16-70 years (adult). For practical implementation of this recommendation, dose coefficients and habit data for a 1-year-old infant, a 10-year-old child, and an adult should be used to represent the three age categories. In a probabilistic assessment of dose, whether from a planned facility or an existing situation, the Commission recommends that the representative person should be defined such that the probability is less than about 5% that a person drawn at random from the population will receive a greater dose. If such an assessment indicates that a few tens of people or more could receive doses above the relevant constraint, the characteristics of these people need to be explored. If, following further analysis, it is shown that doses to a few tens of people are indeed likely to exceed the relevant dose constraint, actions to modify the exposure should be considered. The Commission recognises the role that stakeholders can play in identifying characteristics of the representative person. Involvement of stakeholders can significantly improve the quality, understanding, and acceptability of the characteristics of the representative person and the resulting estimated dose.     

Basic anatomical and physiological data for use in radiological protection: reference values. A report of age- and gender-related differences in the anatomical and physiological characteristics of reference individuals. ICRP Publication 89

This report presents detailed information on age- and gender-related differences in the anatomical and physiological characteristics of reference individuals. These reference values provide needed input to prospective dosimetry calculations for radiation protection purposes for both workers and members of the general public. The purpose of this report is to consolidate and unify in one publication, important new information on reference anatomical and physiological values that has become available since Publication 23 was published by the ICRP in 1975. There are two aspects of this work. The first is to revise and extend the information in Publication 23 as appropriate. The second is to provide additional information on individual variation among grossly normal individuals resulting from differences in age, gender, race, or other factors. This publication collects, unifies, and expands the updated ICRP reference values for the purpose of providing a comprehensive and consistent set of age- and gender-specific reference values for anatomical and physiological features of the human body pertinent to radiation dosimetry. The reference values given in this report are based on: (a) anatomical and physiological information not published before by the ICRP; (b) recent ICRP publications containing reference value information; and (c) information in Publication 23 that is still considered valid and appropriate for radiation protection purposes. Moving from the past emphasis on 'Reference Man', the new report presents a series of reference values for both male and female subjects of six different ages: newborn, 1 year, 5 years, 10 years, 15 years, and adult. In selecting reference values, the Commission has used data on Western Europeans and North Americans because these populations have been well studied with respect to antomy, body composition, and physiology. When appropriate, comparisons are made between the chosen reference values and data from several Asian populations. The first section of the report provides summary tables of all the anatomical and physiological parameters given as reference values in this publication. These results give a comprehensive view of reference values for an individual as influenced by age and gender. The second section describes characteristics of dosimetric importance for the embryo and fetus. Information is provided on the development of the total body and the timing of appearance and development of the various organ systems. Reference values are provided on the mass of the total body and selected organs and tissues, as well as a number of physiological parameters. The third section deals with reference values of important anatomical and physiological characteristics of reference individuals from birth to adulthood. This section begins with details on the growth and composition of the total body in males and females. It then describes and quantifies anatomical and physiological characteristics of various organ systems and changes in these characteristics during growth, maturity, and pregnancy. Reference values are specified for characteristics of dosimetric importance. The final section gives a brief summary of the elemental composition of individuals. Focusing on the elements of dosimetric importance, information is presented on the body content of 13 elements: calcium, carbon, chloride, hydrogen, iodine, iron, magnesium, nitrogen, oxygen, potassium, sodium, sulphur, and phosphorus.     

Advancing US public acceptance of spent fuel storage and transport: proposed outreach services for ionising radiation education support

Abstract

Expansion of commercial nuclear energy could be one of the future US sources for clean, safe, reliable and economic electricity. However, no federal policy has effectively achieved wide acceptance of nuclear energy, with such policies having fallen victim to the politics of public radiation fears from nuclear energy usage and from spent fuel storage and transport. Many experts have described the foundation of public fear as not so much nuclear technology, but the ionising radiation to which people fear they might be exposed, and this issue has been talked and written about, yet gone substantially unaddressed with respect to public education for more than three decades. In the USA, the Blue Ribbon Commission Final Report is just the latest of clear statements where such an educational need is firmly asserted. The lamentable fact is that no one has made that substantive and concerted effort to do anything about it. Indeed, the only effort seems to have been talk about ‘better communication’, with a focus on risk based communication. Any rejuvenation of public acceptance of commercial nuclear energy in the USA, including spent fuel storage and transport, can only be sustained using a different strategy from that of earlier decades. This paper highlights professional opinion on the radiation fear issue and why current industry efforts in risk based information for and communication with the public have not achieved the desired success. Education to expand the public’s understanding of comparative radiation sources and exposures while ameliorating concern about radiation from nuclear energy is the proposed alternative. In addition, here, the clear linkage between education supporting nuclear energy and facilitating necessary spent fuel storage and transport is unmistakable. The paper summarises a concept for outreach services for ionising radiation education support for application in the US, as well as key elements of such a process: its basis for success, its education content and potential implementation approaches. Comparative radiation education of the public can prove effective using current research, which has been effective in other industries. Additionally, while this discussion addresses the US situation, much of the content is likely applicable to many of the world’s nuclear energy producing countries.     

The 2007 Recommendations of the International Commission on Radiological Protection. ICRP publication 103

These revised Recommendations for a System of Radiological Protection formally replace the Commission's previous, 1990, Recommendations; and update, consolidate, and develop the additional guidance on the control of exposure from radiation sources issued since 1990. Thus, the present Recommendations update the radiation and tissue weighting factors in the quantities equivalent and effective dose and update the radiation detriment, based on the latest available scientific information of the biology and physics of radiation exposure. They maintain the Commission's three fundamental principles of radiological protection, namely justification, optimisation, and the application of dose limits, clarifying how they apply to radiation sources delivering exposure and to individuals receiving exposure. The Recommendations evolve from the previous process-based protection approach using practices and interventions by moving to an approach based on the exposure situation. They recognise planned, emergency, and existing exposure situations, and apply the fundamental principles of justification and optimisation of protection to all of these situations. They maintain the Commission's current individual dose limits for effective dose and equivalent dose from all regulated sources in planned exposure situations. They reinforce the principle of optimisation of protection, which should be applicable in a similar way to all exposure situations, subject to the following restrictions on individual doses and risks; dose and risk constraints for planned exposure situations, and reference levels for emergency and existing exposure situations. The Recommendations also include an approach for developing a framework to demonstrate radiological protection of the environment.     

ICRP放射防护基本建议书的演进及其启示

不断演进的国际放射防护委员会（ICRP）的基本建议书,具体阐述了各个历史时期放射防护的总指导方针与原则,是国际组织和世界各国制定放射防护法规与标准的基本依据。ICRP基本建议书的最新更迭是,2007年底出版的第103号出版物——《国际放射防护委员会2007年建议书》取代了其第60号出版物。本文从放射防护体系,防护体系的应用,权重因子和标称危险系数的更新,剂量评价方法,放射防护最优化,医疗照射防护,环境的放射防护等7方面介绍了2007年建议书的更新特点;同时,从更新取决于认识的深化,完善防护体系没有止境,区别对待是重要的防护方针,正确运用剂量限值,培植安全文化等5方面讨论了建议书不断演进的启示。