ICRP Publication 111 - Application of the Commission's recommendations to the protection of people living in long-term contaminated areas after a nuclear accident or a radiation emergency.

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 longterm contaminated areas resulting from radiation emergencies and nuclear accidents, including radiological criteria followed in carrying out remediation measures.

Scope of radiological protection control measures.

In this report, the Commission recommends approaches to national authorities for their definition of the scope of radiological protection control measures through regulations, by using its principles of justification and optimisation. The report provides advice for deciding the radiation exposure situations that should be covered by the relevant regulations because their regulatory control can be justified, and, conversely, those that may be considered for exclusion from the regulations because their regulatory control is deemed to be unamenable and unjustified. It also provides advice on the situations resulting from regulated circumstances but which may be considered by regulators for exemption from complying with specific requirements because the application of these requirements is unwarranted and exemption is the optimum option. Thus, the report describes exclusion criteria for defining the scope of radiological protection regulations, exemption criteria for planned exposure situations, and the application of these concepts in emergency exposure situations and in existing exposure situations. The report also addresses specific exposure situations such as exposure to low-energy or low-intensity adventitious radiation, cosmic radiation, naturally occurring radioactive materials, radon, commodities, and low-level radioactive waste. The quantitative criteria in the report are intended only as generic suggestions to regulators for defining the regulatory scope, in the understanding that the definitive boundaries for establishing the situations that can be or need to be regulated will depend on national approaches.

[In the field of ionizing radiations, are the dosimetric data satisfactory?]. / Dans le domaine des rayonnements ionisants, les données dosimétriques existantes sont-elles suffisantes?

The quantification of the dose is a key element for the surveillance of radiological exposures of the population. The objectives are the reduction as low as reasonably achievable of exposures, the assessment of the risk in complement to epidemiologic surveys and refining the dose/effect relationship. However, two difficulties should be highlighted: first, the dose delivered into organs or to the whole organism is not directly measurable and second, its translation into risk (cancer hazard, for instance) requires precautions. The questions associated with the development of a good dosimetry depend on metrology, modeling, investigations, management of databases, and give rise to debates with regard to the notion of realism and confidentiality of individual data. This activity experiences deep changes due, not only to the development of techniques and the increasing social demand, but also to changes to the regulations, in particular with the transposition of the European Directive for the protection of the patients (97/43, June 30, 1997) and of the Directive relating to the basic safety standards (96/29, May 13, 1996). Various types of situations are distinguished: professional exposure, public exposure (releases of facilities handling radioactive materials, natural sources, contaminated sites, nuclear test fallouts) and patients'exposure (radiology and radiotherapy). Recent investigations at European or domestic level are mentioned, the purpose of which is to evidence the benefits and lacks, if any, in the dosimetric monitoring for these various types of situations. As a conclusion, orientations are defined and some of them are already applied, following the above-mentioned investigations or works. As the two main sources of exposure for the population are medical (41%) and natural irradiations (58%), the effort of the reduction should first cover these two components. With regard to natural radioactivity, the main stake is to identify the sectors with a high radon potential and to implement the associated reduction means. With regard to patients'exposure, the emphasis should concern the development in radiodiagnostic, of the means required for systematically recording a dose indicator for every radiodiagnostic examination and any radiological operation. Finally, the exposure of workers, which only represents a component of the overall population exposure, should be subject to an on-going attention with regard to data centralization and accessibility.

Methodology and results of the Nord-Cotentin radioecological study.

Epidemiological studies have shown a trend towards an excess number of leukaemia cases in the region of Nord-Cotentin (France) where, in particular, the La Hague nuclear reprocessing plant is located. In 1997, it was suggested that the risk of leukaemia was associated with some aspects of lifestyle, in particular, the consumption of local seafood and use of local beaches. To respond to public concern, the French Ministries of the Environment and Health decided to commission complementary epidemiological studies and a detailed radioecological analysis. The radioecological study was entrusted to a group of experts with various backgrounds (inspectors, governmental experts, operators, experts from non-governmental laboratories and foreign experts)--the Nord-Cotentin Radioecology Group. Its principal objective was to assess realistically the exposure to ionising radiation of young people from 0 to 24 years of age who had lived near the La Hague nuclear reprocessing plant and to estimate their risk of radiation-induced leukaemia from 1978 through 1996, the period covered by the epidemiological studies. The Group chose to use a three-stage approach: reconstruction of the population of young people from 0 to 24 years who resided in the region between 1978 and 1996, assessment of their exposure to all sources of ionising radiation, and estimation of the risk of radiation-induced leukaemia attributable to this exposure. The collective red bone marrow dose due to the discharges from the local nuclear facilities from Nord-Cotentin has thus been estimated at approximately 0.5 man-Sv, which is less than 0.2% of the total exposure to ionising radiation, including natural and medical sources and fallout from atmospheric testing and the accident at Chernobyl. The number of cases of radiation-induced leukaemia attributable to discharges from the local nuclear facilities based on the estimated level of exposure was around 0.002 over this period. This is the best estimate, in the current state of knowledge, of the incidence of radiation-induced leukaemia attributable to environmental exposure to ionising radiation among the young people living in the vicinity of the La Hague reprocessing plant based on mean habits for the population. This estimate must be interpreted in the light of the limitations inherent in the risk assessment process, and some participants in the Nord-Cotentin Radioecology Group have expressed reservations about it. Nonetheless, the number of cases estimated here is low in comparison to the four cases of leukaemia observed during the same period. It is thus very improbable that exposure attributable to local nuclear facilities is implicated to any salient degree in the elevated incidence of leukaemia observed in this region among young people.