Recommendations


Draft document: Recommendations
Submitted by Renate Czarwinski, IRPA -International Radiation Protection Association
Commenting on behalf of the organisation

The approach to comment on the Draft recommendations of ICRP was appreciated by the associated member societies of IRPA. Because of the short time for comments only 4 societies (Society for Radiological Protection (SRP/UK), Belgian Society for Radiation Protection (BVS-ABR), Dutch Society on Radiation Protection (NVS) and German-Swiss Radiation Protection Association (FS)) sent their statements to IRPA. SRP, FS, BVS and NVS welcomes this opportunity to comment on the ICRP Draft Recommendations via the IRPA consultation exercise. We recognise the importance of this document for the future of radiological protection, and hence it is vitally important to ensure that the recommendations are thoroughly reviewed by the practitioner community prior to their adoption by ICRP. ICRP are to be congratulated for seeking the continued involvement of IRPA as they develop their thoughts. All societies mentioned that the draft represents a considerable improvement over previous versions of the draft recommendations, and many of the previous concerns have been appropriately dealt with. However, there are still some areas for further improvement. The SRP and also the other societies highlighted areas in their statements, where they consider that further development and /or clarification is necessary in order to deliver a fit-for-purpose set of coherent recommendations which can form the basis of the future of practical radiological protection. In the opinion of the NVS, the main goal of the new recommendations was simplification of the recommendations. These recommendations don’t reach this goal because: • a lot of new standards were added to the existing standards of ICRP 60, which are however still active, • there is inconsistency in repeated definitions and standards mentioned on different places in the recommendations. It seems likely that the document is a combination of different documents written by more people. • a sentence with 50 words or more is not done (e.g. (56)), • there are too much references to other documents which interrupt easily reading and understanding of these recommendations • there is far too much history in the new recommendations, making the document ‘difficult’ to read: Come to the point! Most people are not interested at all in this material. For those who are, put this in an enclosure. • More stressing that dose constraints are primary tools in all optimisation is okay, however the document gives the impression to replace dose limits with dose constraints. The comments are mainly focussed on the five principal topics posed by the ICRP. Comments on other key areas of interest are also added, together with some detailed comment on the text where it was considered to be particularly helpful. Scope (chapter 2) Although it is explicitly stated that the interpretation of triviality as the 10 µSv/a concept is only one part of the full meaning of this concept, the reader is left with the feeling that this is the only possibility to interpret triviality. It should be noted that the “Annals of the ICRP – The Scope of Radiological Protection Regulations – 02/258/05 spring 2006 version” give a much clearer picture in this regard. In Section 3, “Dichotomous Control”, the ambivalent attitude of society towards natural and man-made exposure situations is outlined and recognised as the basis for defining different levels for exemption in these two situations. In para. 49 of ICRP’s “The Scope of Radiological Protection Regulations” it is explicitly stated that: “The 10 µSv in a year criterion has been widely used for exemption of artificial sources and its acceptance for this purpose is well recognised. For exposure from naturally occurring radioactive materials, the criterion might well be established in the order of 1 mSv in a year.” This means that the concept of triviality should be better explained in Draft Recommendation with respect to both types of exposure situations. It should also be noted that the concept of 10 µSv/a could be better clarified in this context in order not to leave the reader with ambiguous interpretations as to its application. Again, this is better explained in ICRP’s “The Scope of Radiological Protection Regulations” para. 41. There is an important clarification of the 10 µSv concept and should also be included in Draft Recommendations. FS- proposal: Explain and clarify the concept of triviality and the 10 µSv concept by expressing the understanding of ICRP’s “The Scope of Radiological Protection Regulations” also in the Draft Recommendation Whilst the thrust of the arguments regarding exclusion and exemption are correct, the formulation used to underpin exemption requires review as it appears to be stated in the wrong order, thereby giving a false emphasis to risk/dose considerations. As stated in para (46) the key principle is the avoidance of unwarranted control, and the reasons for this are not limited to triviality of risk (and dose). Hence the stated principles for exemption in para (45) are secondary in nature and should clearly be seen as such. SRP-proposal: Perhaps the order of paras (45) and (46) should be reversed? In para (45) it would be helpful to have separate principles for the need for practices to be justified and the need for sources to be inherently safe - these two concepts are not related. The description of the concept of exemption in (42, ii) is in contradiction with (43) and (46). A negligible, or trivial, risk is just one of the reasons to exempt a source. As is stated in (43), regulatory control is not warranted if the societal and economical efforts needed for its application would be disproportional. This is specifically the case for practices with natural radionuclides, where the source may be exempted from control at much higher doses than 10 µSv/y, which are certainly not trivial. A trivial risk of 10 µSv/y should therefore only be considered as a level below which every source should be exempted. NVS-proposal: ICRP should consider rewording of (42), (43), (45) and (46) in order to make the application of the concept of exemption more transparent. The ICRP have issued a separate consultation document on the subject of Scope. Whilst the specific issue is not covered directly in the June draft recommendations, it was emphasised the importance to the practitioner of establishing an absolutely clear, simple and understandable basis for the exemption/clearance of solid materials from regulatory control. This is by far the dominant practical issue in this context. SRP-comment: ICRP must provide a framework for the derivation of a single set of activity concentration values [Bq per Kg] which is capable of public understanding and confidence, and is not undercut by secondary issues and the unnecessary definition of other numerical values (eg exclusion values) which would have the potential to generate confusion. SRP-comment: In recognising the need to establish pragmatic approaches to exclusion and exemption on the basis of inability to control or unwarranted control, it would be helpful to extend this argument to move towards establishing a more general basis for the lower boundary of the radiation protection system of control. This would assist practitioners to focus on those situations which merit attention and hence minimise effort in addressing issues of no real merit. The delineation between planned, emergency and existing situations is well understood. The extent to which there is value in continuing also to use the previous terminology practices and interventions at the same time requires careful consideration – there is a potential for overlap which may be unhelpful. The current draft seems inconsistent in its use of these terms. SRP-proposal: Check the current draft in the use of the previous terminology. ICRP introduces the concepts planned, emergency, and existing to characterise the different exposure situations, instead of practices and interventions. It is argued in para.37 that the latter distinction is now considered as being artificial. NVS is not convinced that this change is justified with this argument, certainly not because the concepts practices and intervention are still used by the Commission. Moreover, as stated in (38) and (39), both the concepts practices and interventions have become widely used in radiological protection and have been incorporated in national and international standards. NVS comment: NVS believes that such a change is in contradiction with the third primary aim of the revised recommendations, as stated in the Preface, unless the reasons are better explained. We understand the ‘radon’ is somewhat difficult to include in the old system of practice and intervention, However, don’t change a system because of an exemption. Make it an exemption! NVS-proposal: Give a more and better explanation of the principles of protection (para.30) NVS-proposal: (42) Last sentence: Explain the exemption of legal persons NVS-comment In (37), there is a reference to section 5.4, but we believe that the right reference is to section 5.2. Justification SRP-comment: We agree that justification falls within the sub heading Source Related in para (185), and that such a distinction is helpful. SRP and the other societies believes that it is fundamentally important to retain the principle of Justification, and expressed their opinion that the treatment in the current draft gives the correct sense and weight to this topic. In particular SRP supports the requirement for justification to be considered generically, ie by type of practice or activity. However, whilst the final sentence in para (190) is self evident [Radiological protection considerations will be important to a greater or lesser extent …], their experience indicates that in almost all situations radiological issues are minor compared to other factors. Indeed, the formal inclusion of the concept of justification in radiological protection philosophy and regulation has in practice served to highlight and unduly emphasise the radiological risks and set them apart from other hazards which in practice may be more important. SRP-comment: Hence it is important that para (190) emphasises the broad all-encompassing nature of justification and that potential radiological hazards are only one (probably small) factor in the considerations. In para (247) it is important to emphasise that an individual patient exposure can only be justified if the outcome of the delivery of the exposure is evaluated for the benefit of the patient. In diagnosis this means that a clinical evaluation of the image acquired must be carried out otherwise the exposure is not justified. SRP-comment: There is a strong support for the specific attention given to the justification of medical exposures. The statements under para.188-191 remain rather vague and unclear and as already mentioned in its previous comments, the working group does not understand the Commission’s motivation for making an explicit difference between medical and other exposures in relation to justification. For both medical and professional exposures a clear distinction can be made between the generic and a particular justification and the nuclear industry holds many examples of particular exposures that were judged not justified although the production of nuclear energy is generically justified. BVS-proposal: reformulate paragraphs 188-191 by making a clear distinction between ‘generic’ justifications that fall under the responsibility of governments or governmental agencies and justification at the lower-level of specified procedures or the application of specified procedures, that fall under the responsibility of the operators or practitioners. No distinction between medical/occupational/public exposures needs to be made. Optimisation and dose constraints (incl. individual comments on chapter 5) The draft recommendations appropriately highlight the central importance of optimisation as the cornerstone of practical protection. However, the descriptive wording associated with the concept has become over-indulgent and unnecessarily complex. Para (193) adequately and appropriately expresses the necessary definition, which remains focussed on the well-recognised and respected ALARA terminology. SRP-comment: Other expressions such as the ‘principle’ statement in para (185) are unnecessarily complex: in particular the use of the term best protection option under the prevailing circumstances does not add any value. SRP fully agrees with the sentiment expressed in para (194) that optimisation must reflect the role of individual equity, safety culture and stakeholder involvement. This is in line with considerable UK experience in this field over many years, and the artificially narrow interpretation of optimisation resulting from the older referenced ICRP reports is not representative of recent or current practice. Quantitative methods are referred to only in para. 194 with the short hint to ICRP 37 and ICRP 55 which are described as still valid. It would be highly desirable that the reference to quantitative methods be more directly in the text of the new recommendation. FS-proposal: Para. 194: Extend “…remain valid. The decision aiding techniques are still essential to find the optimised radiation protection solution in an objective manner; this includes methods for quantitative optimisation such as cost-benefit analyses.” The wording concerning optimisation and dose constraints used by ICRP often cannot be clearly interpreted by professionals in radiation protection. Both topics are interrelated, but the ICRP recommendation is not very clear on this issue. On the one hand, dose constraints belong to the optimisation, while on the other hand, dose constraints are the starting point for optimisation. Though addressed at many places in the document, the topic of dose constraints is not clearly discussed. For example, no recommendations on how to derive dose constraints are given. They should not be the result of optimisation and not simply a pre-defined fraction of the dose limits. While it is outlined what dose constraints are not, no statement on what they are is made. If the dose constraints fulfil a central role in radiation protection, it would be highly desirable to have clearer statements on their definition and setting. FS-proposal: Give more guidance for the process of defining and setting constraints SRP-comment: SRP emphasises the need for further reflection on the relationship between constraints and limits, and on the role of prospective constraints during ongoing operations and retrospective analysis. NVS-proposal: Give an explanation of source related dose constrains (planning dose?) SRP agrees in principle with the use of source-related constraints as a key component of the prospective optimisation process. However, the key issue in practical implementation is the extent to which constraints are regarded as de facto ‘source limits’ - in effect having the same status as limits in terms of operational compliance. Where constraints are prospectively set in advance of operational activity, presumably on the basis of generic optimisation considerations as outlined in para (210), there will be a strong tendency to regard the numerical constraint as the operational limit, regardless of actual experience. This could lead to a mis-allocation of resource aimed at compliance with a perceived ‘limit’. SRP-proposal: It is essential to give further clarification of the status of constraints in relation to operational activities, and to emphasise more strongly the need for continued review of the choice of the constraint during the operational life of an activity. It is clear from the text of chapter 5.8 that the ICRP wants to put more emphasis on constraints, but the real purpose of this trend is not straightforward; is it only to avoid to create inequities resulting from the optimisation process, like mentioned in (185) and in (199), or are there other motivations (e.g. constraints can be seen as ‘reference levels’, in order to stimulate the optimisation process) ? BVS-proposal: Summarise somewhere the real purposes that should be found behind the application of dose constraints. The extension of the concept of constraints to emergency and existing situations, thereby replacing the intervention action levels, is still a matter of concern. In the current recommendations the action levels represent the dose above which an intervention is almost always warranted, i.e. the upper level of an intervention band, and the intervention should be optimised to achieve the highest benefit of the action. In the proposed system, the constraint represents the dose level below which regulatory action, i.e. optimisation, should be exercised. NVS-comment: Does this imply that for every existing situation causing an exposure below the dose constraint, and which is not excluded or exempted, an optimisation is required? NVS-comment: Moreover, the upper band of 100 mSv is 5 times lower that the currently used high level for evacuation. As you know an evacuation is almost permanently, and so relocation, after 6-12 months. We dont think that such low levels can justify that. The concept of dose constraints for planned situations has been introduced in the current recommendations, but the implementation of the concept in national regulations up to now has shown to vary considerably in different countries. A recent survey of the European ALARA Network of the implementation of the concept in European national regulations showed that the concept is misinterpreted in quite some occasions, sometimes caused by difficulties in translating the term constraint in the national language. It is highly questionable if the extension of the concept to emergency and existing situations will be seen as a simplification of the system and thus leading to a better In para. (201) the Commission refers to dose constraints for existing and emergency situations that, in some rare exceptional situations, could be higher than any dose limit. It is confusing to make this comparison with dose limits, which are only applicable to planned situations. It strengthens the impression that the dose constraints can play the role of dose limits in certain situations. This impression comes also from (198) in which it is stated that the dose constraint is the most fundamental level of protection, and that the intention of the optimisation process is to result in exposures that are below the relevant dose constraint. The use of the dose constraint should be flexible, certainly for existing and emergency situations. The Commission places too much emphasis on the role of constraints in the radiation protection system. In our view, it is the other way around: the most fundamental level of protection is provided by the optimisation process, in which the dose constraint is only a tool to avoid inequity. NVS-proposal: In (205) the Commission states that "the second band .... applies in circumstances where individuals receive direct benefits from the exposure situation ...". This is not very likely to be the case in the emergency situations to which the last sentence refers. This should be reworded. NVS-proposal: Also the last part of the first sentence of (206) ("... where the source cannot be controlled.") should be reworded. It is no use to set constraints on such a source. This is also the case for Table 4, where in the band 20-100 mSv the situation is characterised as "either not controllable or where actions to reduce doses would be disproportionately disruptive". This problem is particularly acute in dealing with occupational exposure, where operational control is principally based on assessing the total dose to workers from all relevant sources. Such control, including the integral ALARA process, sometimes takes account of knowledge of exposure to specific activities within the work programme, but in practice it is the total exposure which is the key control parameter. SRP-comment: ICRP’s emphasis on constraints as the most fundamental level of protection does not fully align with operational practice for occupational exposure. The objective of setting constraints, e. g. as formulated in para. 210, remains unclear and gives rise for arbitrary selections. Following the recommendations dose constraints have the objective – to assure compliance with dose limits in case of more than one source giving rise to exposure to one person, – to prevent too high individual doses even as the result of an optimisation process. It might be questionable that one needs dose constraints at all to achieve these goals. The objectives above have been adhered to ever since radiation protection limits exist, already at times when no formal dose constraints have been used, without compromising safety. Dose constraints shall neither substitute nor preclude optimisation. Therefore, they should not be derived from already optimised practices as expressed in para. 210 with reference to “good practice elsewhere”, which implies that already optimised radiation protection solutions “elsewhere” exist. This is contradictory to the demand to optimise below the constraints. FS-proposal: The reference to “good practices” should be deleted. SRP agrees with the proposed approach that the selection of the specific value for the constraint may be established by a process of generic optimisation that takes account of national or regional attributes and preferences together, where appropriate, with a consideration of international guidance and good practice elsewhere (para 210). SRP also supports the approach in para (203) et sec on defining numerical values within three broad bands based on relevant attributes. SRP-proposal: SRP would encourage the re-introduction of a minimum value to the first band [ie the ‘under 1 mSv’ band] as part of the suggested consideration of the lower boundary to the system of control. The new table 4 on page 61 presents a system of dose constraints changing from “maximum dose constraints” in the 2005 draft of the ICRP recommendation to “bands of projected effective dose”. a minimum value of a constraint in the band “under 1 mSv/a” is explicitly missed. FS-proposal: Introduce a value of 0.1 mSv/a as minimum value for a constraint in the band below 1 mSv/a. NVS-comment: The explanation in table 4 is not carefully formulated. However, given the above broad approach to the setting of numerical values for constraints and the emphasis on the need for local involvement in the process, SRP disagrees with ICRP’s re-adoption of detailed numerical constraints in the specific field of waste management - ie 0.3 mSv and 0.1 mSv taken from Publications 77 and 82. ICRP’s adoption of these values and their scientific underpinning, together with the associated value judgements, has not been subject to the rigorous review and consultation process now espoused so strongly by ICRP. Whilst the numerical values are not unreasonable in a UK context, their re-adoption by ICRP at the international level seems to go against its fundamental approach whereby constraints should be established by a process of generic optimisation that takes account of national or regional attributes and preferences (para 210 as above). SRP-proposal: It is essential that such constraints should be defined at the local/national level with involvement of relevant stakeholders. Appropriate text could read “The Commission now recommends, in conformity with the principles expressed in para (210), that these specific values are used for guidance subject to consideration of national or regional good practice”. Although much is said in para. 197 it will not be sufficiently clear that dose constraints are not intended to take the place of new and lower limits. Dose constraints can be a helpful tool while planning any practise and they also can be used to find out retrospectively, if there was any essential deviation from the plan. But this is a very crucial point: If dose constraints take the role of a dose limit, then non-compliance can have significant consequences for any use of radiation sources. In such a case, the actual limits would de facto be reduced to an arbitrary fraction of the current limits. However, this would be a substantial misinterpretation of the role of dose constraints. The risk estimates on which the dose limits have been based have not changed. The risk estimates define the dose limits, not the dose constraints. Therefore, any change of the limits will be inappropriate. FS-proposal: Extend para. 197 as follows:“…section 5.8.1 below. They are intended neither as a form of retrospective nor prospective dose limitation,…” The objective of optimisation is defined in different paragraphs of the document in different ways, making it difficult to implement optimisation in practice. The formulations in - para. 30 : “level of protection should be the best, maximising the margin of good over harm” - para. 197: “appropriate level of protection” - para. 221: “questioning whether the best has been done under the prevailing circumstances”, do not describe the process precisely and consistently, but evoke the questions: What means “the best”? Does it mean the “lowest dose”? FS-proposal: The process of optimisation has to be described more precisely in all relevant paragraphs and consistently by taking into account para. 227, which states: “Optimisation is not minimisation; the best option is not necessarily the one with the lowest dose.” Para. 226 contains the statement, that a lower bound for optimisation cannot be defined. However, it should be clearly stated in this context that doses below some 10 µSv/a are insignificant and trivial and therefore need not be regarded when performing the optimisation process. FS-proposal: Para. 226: It is recommended that the optimisation process should end in the range of 10 µSv/a. Results with doses below this value should automatically be considered as optimised. Para (226) discusses whether it is possible to determine a dose level below which optimisation should stop. Whilst we agree that this is difficult to decide a priori, it would be appropriate to indicate that the greatest attention should be focussed on those situations where the exposures are closest to constraints and that there is clearly a situation of diminishing returns in terms of health benefit when exposures are insignificant compared to other generally unavoidable exposures. SRP-comment: There is a need to give more thought to establishing a more general basis for a lower boundary to the system of control. In the ICRP document, optimisation is defined as a process with attributes as follows: – ongoing, cyclical (para. 196), – interactive, continuous (para. 221), – interactive and iterative (para. 197). This may indeed be the case for some complex cases. For most applications in everyday practices, interactive, cyclical or iterative elements in the optimisation process would result in a totally undue burden. Having achieved a certain level of exposure a practice should be regarded as optimised and only in longer periods or after unusual events or after some significant new experience has been gained, the radiation protection situation should be re-evaluated checking whether the process is still optimised. FS-proposal: Para. 196: extend the first bullet point “Evaluation of the exposure situation in cases where the circumstances relevant to the optimisation process have changed significantly.” SRP-comment: The interaction between optimisation and constraints is critical - indeed they are integrally bound together as illustrated by the optimisation process outlined in para (196). The use of collective dose in societal decision making processes does need circumspection if equity is to be maintained with the treatment of other hazards which are not amenable to equivalent assessments. SRP-comment: Supporting the comments on the limitations and usage of collective dose in paras (229) to (231), and also in paras (57) and (145) to (148). SRP-comment: Para (227) is helpful in emphasising that optimisation is not minimisation. SRP-proposal: In para (248) the second sentence could be usefully expanded to state “In diagnosis, this means avoiding unnecessary, or greater than necessary, exposures, while in therapy…” further emphasising the need for an integrated approach to justification and optimisation in diagnostic exposures. Chapter 5.1 is titled “The definition of a single source”, but in paragraphs 160 and 161 it is only discussed how the term “source” should be understood. No explicit definition of what the ICRP considers as a “source” is given. This could create some misunderstanding, especially as the term “source” could be confused with the use of “radioactive sources” or as distortions are possible, as mentioned at the end of paragraph 161. BVS-proposal: Define explicitly in chapter 5.1 what is considered as a “single source” regarding the further discussion about the system of protection. Chapter 5.9 starts with the statement: "Dose limits apply in planned situations". From this, the working group understands that the limits are not applicable to emergency situations and to existing exposure situations. But the para. 240 mentions: "Dose limits do not apply in situations where the exposed individual is engaged in life saving actions or is attempting to prevent a catastrophic situation." This statement is then too restrictive and creates an ambiguity. BVS-proposal: Replace the sentence in paragraph 240 by: "Dose limits do not apply for emergency situations and in existing exposure situations. The guidance given in section 11 would apply in such situations." Clarify eventually in the definition of planned situations (162) that recovery operations after an emergency should be considered as a planned situation. Natural sources of radiation (incl. individual comments on chapter 7) SRP-comment: The approach to natural sources is broadly supported. Since ICRP had been criticised for the insufficient depth of representation of this matter in its 2004 draft recommendations the Commission now presents a revised version in which a whole chapter is devoted to the topic. The recommendations concerning natural radiation sources are now better structured and some of the intentions are presented more clearly than before. The representation depth is now adequate considering the importance of the natural radiation exposures. Nonetheless, there are still a number of problems, both on the conceptual level and in detail – up to unclear terms. NVS-proposal: The section “Type of exposure” (as well as (288) in the next section) does not address recommendations, but only gives an overview of natural exposure situations. It should be deleted, or else revised drastically. The choice of the expression type of exposure seems to be unfortunate. After types of exposure situations para. (5.2) and categories of exposure para. (5.3) another, very similar term is introduced having obviously a different meaning. FS-proposal: To avoid confusion, a new headline should be devised for the section. One of the major positions of the Commission is expressed in para. 291: (291)… The distinction between ‚natural’ and ‚man-made’ or ‚artificial’ radiation exposure has proved to be peculiar and unconstructive’.It is true that the differentiation between exposures due to natural radiation sources on the one hand and due to artificial sources on the other hand sometimes leads to difficulties in interpretation. As far as the fundamental principles of protection are concerned, the demand for coherence and consistence is, therefore, to be appreciated. This should be no reason, however, to underestimate the particularities (para. 291) of natural radioactivity, especially its ubiquity. These particularities should rather be pointed out even more clearly, because the resulting consequences can be considerable. For instance, a complete equality of treatment might lead to the demand to evaluate NORM in the same way as materials for clearance, that is, on the basis of the 10 µSv/a concept, which would be unfeasible in many cases. Also, the fact that exposures to radon in dwellings, to natural radiation in drinking water or building materials affect the whole population is an important particularity and leads to the necessity of specific regulations. The recommendations concerning radon (para. 298) naturally stress these particularities. Thus, the claim cited above is not consistent with the ICRP recommendations themselves. FS-proposal: Delete the above cited sentence of par. (291) There is debate in paras (291) and (292) on the unconstructive division between natural and man-made/artificial sources and the resulting dichotomous scale of protection. Despite appearing to regret this position, the approach of ICRP is then to embed and re-inforce the dichotomy. Whilst acknowledging that this is a difficult situation and reflects differences in both source controllability and public perception, it is unfortunate that ICRP take such a passive line without any proposals as to how the dichotomy could be ameliorated or addressed in the longer term. SRP-comment: The principal concern here is ICRP’s apparent re-inforcement of the perception that artificial sources require particularly tight control compared to natural sources, which SRP does not believe to be the intent. Note that this issue is compounded by para (341). NORM Problems arise from the attempt of ICRP to assign radiation exposures due to natural sources of industrial origin (NORM) to either ‘planned’ or ‘existing’ situations. According to para.288. New facilities processing ores enriched in radionuclides ... are ‘planned’ situations. Apart from the fact that significant radiation exposures are often caused by residues from industrial processes (TENORM) rather than ores, they often arise from the deposition or release of these residues in the general environment. However, exposures to natural sources in the general environment are considered to be ‘existing’ situations according to para.278. FS-proposal: To avoid such contradictions, ICRP is asked to abstain from such strict assignments to one of the categories ‘planned’ or ‘existing’. It should rather be conceded that such a distinction is not always clear. It should be left to national regulatory bodies to decide whether such assignments are deemed reasonable and necessary. The listing of industries in para. 282 is of little help, since other industries / residues may be of comparable relevance. On the other hand, for instance the milling of mineral sands is of importance only for some minerals, containing enhanced levels of natural radioactivity. FS-proposal: It should be pointed out that the mentioned industries are only examples. Moreover, the parts of para.282 concerning NORM seem to be not sufficiently consistent with para. 288. For example, the processing of ores is mentioned in para.288 but not in para.282. It should also be mentioned that radiologically relevant residues may result from the processing of ores not enriched in radionuclides, too (e.g. dusts from off-gas cleaning of blast furnaces in raw iron and non-ferrous metal processing). The term TENORM is widely used for such NORMs. FS-proposal: It seems sensible to mention this term at least and clarify its relation to NORM somewhere in the recommendations. Exclusion and Exemption with respect to natural sources The recommendation that naturally occurring radionuclides in most materials .. below 1000 Bq/kg for the heads of uranium and thorium series (para. 294) be excluded from the radiation protection system because the exposures are not amenable to control is in clear contradiction to experiences gained in Germany (Wismut rehabilitation, NORM), whether the concentration is unmodified - as in waste rock piles - or not. The term exclusion is, therefore, not appropriate in this situations. Such materials could possibly be exempted, provided that resulting exposures be generally sufficiently low. For large volumes of materials, however, exposures well above 1 mSv/a may result even from concentrations below the given values. This has been demonstrated by a number of radiological studies, including those of the European Commission, RP 122 part II. Also, it is this very reason that caused the IAEA in its Report SRS 44 (‘Derivation of Activity Concentration Values for Exclusion, Exemption and Clearance’) of 2005 to confine the validity of the value to situations “excluding the emanation of radon and cases of bulk volumes contaminating water pathways, which could require case by case evaluation of possible doses“. Proposal: ICRP should abstain from the definition of such values. Alternatively, it could be recommended that national regulatory bodies define such exclusion values themselves, taking into account country specific conditions like the upper levels of radioactivity concentrations in soils. An appropriate level could be 200 Bq/kg. In the case of mentioning the 1000 Bq/kg value furthermore, the preconditions under which it is to be applied should be added. The suggested exclusion levels in paragraph 294 of 1000 Bq/kg for the uranium and thorium decay series and 10,000 Bq/kg for K-40 can in particular circumstances lead to significant controllable doses. Typical examples are: • The use of building materials in bulk amounts approaching the suggested exclusion levels can, according to Radiation Protection 112 of the European Commission (1999), lead to effective doses of more than 10 mSv/year to the inhabitants. • The conversion of an area contaminated with natural radionuclides approaching the suggested exclusion levels into a residential area can lead to effective doses to the inhabitants up to 10 mSv/year (e.g. a phosphogypsum deposit). From the above examples it is clear that the suggested exclusion levels cannot be generally applicable. Therefore they should be deleted from para. 294 or there should be a statement added in para. 294 "that there are circumstances where these exclusion levels could not be appropriate (e.g. bulk building materials, large contaminated areas)". BVS-proposal: Delete the exclusion levels for naturally occurring radionuclides in paragraph 294 or add a statement that there are exposure situations where these exclusion levels could not be appropriate (e.g. bulk building materials, large contaminated areas). Para. (294) deals with exclusion of natural sources, and should be redrafted considerably for the following reasons. Although NVS welcome the adopted values for activity concentration of the natural radionuclides below which the sources should be excluded from control, the ICRP does not give any explanation why these values are considered to be the right dividing line between controllable and uncontrollable sources. Neither does NVS understand why these values are only applicable for exclusion of unmodified concentrations. What happens when such materials are modified and the concentrations are still below the values quoted in this paragraph? Are they no longer excluded after modification? NVS-proposal: It should also be mentioned that natural radionuclides in building materials, just as in food stuffs, drinking water and animal food, should be regulated in a separate way, instead of being exceptions of the exclusion level values. NVS-comment: The reference to Chapter 10 in para. (294) is unclear. The exclusion level of 40 Bq/m3 for Radon-222 concentrations in dwellings in the same paragraph corresponds to the global mean value of residential radon concentrations. At first sight, this level does not seem to be unreasonable, the more so as the value corresponds to an effective dose close to 1 mSv/a (7000 h/a). However, a certain danger exists that this value is misinterpreted that way that concentrations exceeding this value need to be regulated in principle. In Germany, for instance, this would not be feasible. Here, radon concentrations below 100 Bq/m3 are considered to be not amenable to control because of unavoidable contributions from the free atmosphere and from building materials. FS-proposal: ICRP should abstain from the definition of a fixed value. Instead, regulators should be advised to define country-specific values (see also 2.5). SRP-proposal: It is not clear how para (295) relates specifically to natural sources. The para is more generally applicable and should perhaps be included in the section on Scope. SRP-comment: Paras (296) and (297) seem to relate more to Section 3 on biological aspects and risks. BVS-proposal: The exemption of sealed sources in paragraph 295 with a dose rate less than 1 µSv/h at a distance of 0.1 m has especially to do with artificial sources and should therefore be placed in another chapter. The exemption in paragraph 295 of any amount of material with a dose rate less than 1 µSv/h at a distance of 0.1 m has no sense for alpha and beta emitters and questionable for gamma emitters. BVS-proposal: Delete paragraph 295 entirely or transfer part of it to another chapter. In any case the exemption any amount of material with a dose rate less than 1 µSv/h at a distance of 0.1 m has no sense for alpha and beta emitters and questionable for gamma emitters. Para. (295) deals with exemption, but is of a generic nature and has nothing to do with natural sources. Instead of that, a paragraph should be written which specifically deals with exemption grounds for natural sources. Exemption should be possible for natural sources above the exclusion levels, but where the resulting exposure leads to doses below a certain constraint, say 1 mSv/y. Even above such a constraint, the natural source might still be exempted when the dose is considered to be the optimum. NVS-proposal: When the source is not exempted, a graded approach or regulatory control, as mentioned in paragraph (290), should be applied. Both the numerator and the denominator in the calculation of the conversion conventions for public and occupational exposures in ICRP 65 have been superseded (paragraph 299-301). Indeed, the numerator, which is based on the epidemiological studies of miners, was recently replaced by the pooled residential case control studies, as indicated in paragraph 297; while the denominator, the detriment associated with a unit effective dose, is superseded by table 2 on page 24 of this report. All the scientific evidences (numerator change, denominator change, dosimetric approach) point away from the ICRP 65 conversion conventions in the direction of the UNSCEAR conversion factor of 9 (nSv/h)/(Bq/m³) radon progeny exposure. Moreover, the average global exposure given in paragraph 283 of 2.4 mSv/year is calculated with the UNSCEAR conversion factor, which is 50 % higher than the ICRP 65 conversion convention for members of the public. Using the ICRP 65 conversion convention would result in an average global exposure of 2 mSv/year. For all these reasons it is only natural to replace the ICRP 65 conversion conventions by the long established UNSCEAR dose conversion factor. BVS-proposal: Replace in paragraphs 299-301 the superseded ICRP 65 conversion conventions for public and occupational exposure by the UNSCEAR conversion factor of 9 (nSv/h)/(Bq/m³) radon progeny exposure. The definition of constraints is aimed at the reduction of high radon exposures for a comparably small number of persons affected (it is understood that the value of 600 Bq/m3 is an example for the definition of such a constraint within the band given in Table 4). Newer concepts for the protection against radon in dwellings have been developed meanwhile which are based on the premise that the exposure to radon in homes should be in principle as low as possible for the population as a whole, because this is expected to be most effective from the standpoint of health-politics (WHO). For reasons of feasibility, of course, lower bounds of the regulated concentration range should be defined taking into account country-specific conditions (see 2.3). FS-proposal: Introduce the following additional paragraph (after current para. 302): “Considering the newer epidemiological findings and the fact that radon exposures affect the population of a country as a whole [the ICRP believes] that it is prudent from the standpoint of sound health-politics not to confine the protection against radon at home to the reduction of exposures exceeding the constraints defined by the national regulators but to strive for a general reduction of radon exposures for the population as a whole. Under the aspect of optimisation graded protective measures might be appropriate depending on the radon concentrations. Exclusion levels might be defined on a country-specific level below which protective measures are likely to be not reasonable.” NVS-proposal: Paragraph (296) and (297) deal with epidemiology and should be placed in Chapter 3. It is not possible to assess the radiation dose from inhalation of thoron decay products by epidemiological means and therefore it must be estimated using dosimetric modelling. For consistency reasons it seems reasonable to adopt in paragraph 304 for thoron decay products the UNSCEAR dose conversion factor of 40 (nSv/h)/(Bq/m³). BVS-proposal: Adopt in paragraph 304 for consistency reasons the UNSCEAR dose conversion factor of 40 (nSv/h)/(Bq/m³) for thoron decay products. Existing situations It seems unclear what is meant by the formulation radiation sources of natural origin. Are industrial residues (e.g. TENORMs, compare 2.2) of natural origin? FS-proposal: The term “radiation sources of natural origin” should be made clear in para 340. Other chapters and prinicipal issues Biological Aspects of Radiological Protection (chapter 3) FS pointed out that the presentation of the "Biological Aspects of Radiological Protection" has been considerably improved and some of the somewhat incoherent argumentations in the for¬mer version are now pointed out more concisely. The convention of Linear-No-Threshold (LNT) is emphasized to represent a radiation-protec¬tion standard rather than a mechanistic effect model (para. 55-57). At several sites it is made clear that this "hypothesis" (para. 56) is judged to be a reasonable assumption "for the purposes of radio¬logical protection" (para. 55). "Biological information that would ambiguously verify this hypothesis is unlikely to be forthcoming" (para. 57). It is extraordinarily worthwhile being emphasized that it is not appropriate to calculate by means of LNT the hypothetical number of cases of cancer or heri¬table disease that might be associated with very small radiation doses (para. 57). The recommended nominal probability coefficients (para. 72-75) represent a weighting of the incidence probabilities with lethality and with quality-of-life detriment. This procedure has a number of advantages und yields considerable improvements to ICRP 60. For the first time, the coeffi¬cients are based on incidence data being more reliable than former mortality data. Furthermore, improved healing methods, different prognoses for various cancer sites, and other develop¬ments that involve the relationship of mortality and incidence are considered and integrated appropriately. In the former draft, the procedure of the determination of the coefficients was not clear in each aspect. In the present version combined with Annex A the concept of lethality weighting and quality-of-life detriment is considerably more streamlined and improved. The public view to the "nominal probability coefficients" is that they stand for something like "radiation risk". Thus, the advertency -the scientific as well as the public- towards these quan¬titative values now obtained, (para. 72) Table 2, is going to be very pronounced. This is true for both, the values itself and in comparison with the corresponding quantities of ICRP 60. The central value of the latter, often cited and most frequently discussed, was the nominal risk coefficient for fatal cancer in the whole population given with 5% per Sv. Although "the present detriment-adjusted nominal risk coefficient for cancer … has been computed in a dif¬ferent manner from that of Publication 60" (para. 73) the corresponding projection for fatal cancer now is given as 4% per Sv (73). This value can not be retraced or calculated straightforwardly neither from the present text nor from Annex A (Table 4.1 and text). FS-proposal: A clear figure of how this value is obtained should be given because the reduction of 20% compared to ICRP 60 is of considerable concern and will be discussed very extensively and controversially. At present the most commonly cited indication of quantitative radiation induced "risk" is the value of 5% per Sv for fatal cancer. Henceforth, the one-for-all risk indication will be 6% per Sv for (lethality adjusted) incidence probability. Thus, although the direct comparison of the cor¬responding former and present values results in a reduction, a modified interpretation of risk indication leads to an increase. FS-proposal: This confusing reorientation has to be pointed out more clearly. The argumentation in this regard in para. 75 seems to be too vague and imprecise. FS-proposal: According to Annex A, in Table 2 (para. 72) the present values for the total effect (next to last column) have to be changed in 5.7 (instead of 6) and 4.2 (instead of 4), respectively. Radiation-induced genetic risk In paragraphs 67 and 68, the 0.2% per Gy figure (risk up to the second generation) after continuous low dose-rate exposure over two generations is claimed to be essentially the same as that cited by UNSCEAR 2001, with reference to table 46 of UNSCEAR 2001. Note that this table gives the estimate from one-generation exposure (risk for continuing exposure being given in table 45). There is also a risk of confusion when speaking about the risk “up to” the second generation, suggesting that this is a cumulated risk and that it will be fully expressed in two generations. In the context of continuing exposure, table 45 gives the risk “in” the second generation, based on the evolution of the mutation component (see UNSCEAR 2001, paragraphs 505 and 437). With continuous exposure in subsequent generations, mutation component (and disease frequency) will continue to increase to attain a value of 1 at the new equilibrium (UNSCEAR 2001, figure V, p. 40). Finally, for obtaining the 0.2% per Gy figure, a reduction factor of 0.4 is applied to take into account the genetically significant dose in a global population: this is explained in the foundation document but not mentioned in the main text. Now, can we say that the genetic risk is practically limited to the two first generations? ICRP defends this view in paragraph 67 and supports it (in the foundation document) by radiobiological data suggesting that the major contribution to the genetic risk comes from multigene deletions expressing themselves essentially in the two first generations by multi-system developmental abnormalities and by the numerous uncertainties involved in the estimation of the long term genetic risk (“for tens or hundreds of human generations”). In fact radiation-induced DNA lesions are not always “multigene” deletions and the “short term” hereditary effects are not limited to multi-system developmental abnormalities and dominant diseases in the two first generations. When the chronic multifactorial diseases are left aside (as it was the case in UNSCEAR 1988 and 1993), the “equilibrium” risk coefficients are not significantly influenced by population changes over hundreds of years, but mostly by the selection effect for the most important component, i.e. the autosomal dominant/X-linked diseases, and this equilibrium is obtained after 5 to 6 generations (UNSCEAR 2001, figure V, p. 40). Even if we consider that the “weight” of the 2 first generations is preponderant, it would be by far more acceptable to take explicitly all the autosomal dominant/X-linked diseases into account, as it was done in the past. Finally, considering the numerous uncertainties involved for not estimating the long term genetic risk, it seems paradoxical to recognize that considerable uncertainties still exist in this field, while concluding that enough is known as regards the mechanisms of radiation-induction of genetic effects to allow ignoring the possibility of significant long term risks. The basic question is whether we know enough about possible long term radiation-induced genetic effects to close this matter and to take now the effect on the generations over the second as being zero. BVS-proposal: ICRP should more clearly underline that: • on comparable bases, the genetic risk has not decreased; • if the choice of a risk estimation for 2 generations only can be justified in the context of the calculation of effective dose for comparison with dose limits, long term genetic risks must be taken into account for judgments about continuous exposures affecting consecutive generations; • due to the numerous uncertainties, keeping gonadal doses ALARA is still strongly recommended (current sentence in paragraph 68 should be repeated in the relevant sections); • the current risk estimate is for a total population, not for a reproductive . Risk of in utero irradiation After irradiation during the pre-implantation period, generally considered as safe with regard to the radiation-induced risks, non lethal congenital malformations have been induced in animals, particularly (but not only) in those with a genetic predisposition to specific congenital malformations or with genetic disorders in the pathways of DNA-repair. Moreover, during the zygote-stage (about 1 day), there could be no threshold dose for the radiation-induction of congenital malformations in genetically predisposed animal strains. After irradiation during the organogenesis, more congenital malformations have also been induced in animals with genetic disorders, and there are similarities with the effects of chemical agents. In these cases, the cause of the congenital malformations may not be an increased loss of cells (classic deterministic effect) but rather the persistence of un-repaired or mis-repaired DNA-damaged cells (“teratogenically damaged cells”). Now, in humans, the same genetic susceptibilities probably exist: there are indeed families showing clusters of spontaneous congenital malformation. There are also in humans many genes implicated in the DNA-damage response and involved in the genetic susceptibility to cancer induction by irradiation; if the mechanisms are similar (persistence of mis-repaired DNA-damaged cells), it is plausible that human genotypes leading to cancer-proneness are also associated with a genetic susceptibility to the radiation-induction of congenital abnormalities (or more subtle tissue dysfunctions). Due to genetic susceptibilities, there could then be for some individuals a higher risk of radiation-induced malformations (or dysfunctions) or lower thresholds (or even no threshold at day 1?) and this risk could also exist during the “safe” periods of pre- and early post-implantation (when women are not aware of being pregnant). Although frequently assumed to be low, the frequency of these individuals is not known. This raises doubts about the “definite” and generalized character of the 100 mSv threshold dose for lethal, developmental or other detrimental effects after irradiation during the first trimester of pregnancy, currently applied by many as a practical criterion: this could be an unjustified simplification. Furthermore, 100 mSv to the foetus/embryo can be regarded as related with a very significant risk of radiation-induction of cancer! BVS-proposal: ICRP should: • more clearly underline the uncertainties in the evaluation of the risks after in utero irradiation and in the setting of reliable threshold doses; • emphasize that, due to the numerous uncertainties, keeping embryonic/foetal doses ALARA is still strongly recommended; • be cautious, especially in the medical field and in existing situations, and particularly avoid suggesting the “100 mSv” figure as a global and “definite” threshold for all significant effects. Cataracts New data challenging the current dose threshold for radiation-induced cataracts are now available and sufficient for deriving already now appropriate conclusions. BVS-proposal: ICRP should: • be cautious and not wait for proposing up to date dose limits for the lens of the eye; • recommend appropriate dosimetry in critical practices as interventional radiology. Non-cancer diseases Non-cancer diseases are discussed in paragraphs 86 and 87. Although the summary of the current scientific evidence in paragraph 86 seems adequate, the conclusion drawn in paragraph 87 is more questionable. While it is clear that no definite answer can be given regarding the shape of the dose-response at low dose and regarding the numerical values of possible threshold doses, that situation is somewhat comparable with the situation ICRP faced in the past regarding cancer induction: the uncertainties did not discourage ICRP several decades ago to adopt the LNT-hypothesis and the ALARA-approach. BVS-proposal: ICRP should adopt a more precautionary approach and take explicitly this kind of risk into account in her judgements and protection recommendations, particularly in high dose situations as medical exposures and prolonged exposures. DDREF The question of the DDREF is discussed in paragraphs 61 to 64. ICRP explains the arguments for and against a reduction of the DDREF and recognizes that maintaining a DDREF of 2 for purposes of radiological protection is the result of a broad judgement with both subjective and probabilistic uncertainty. One of the main arguments is the protracted character of the exposures incurred. However the ICRP system of radiological protection covers not only situations with chronic or protracted exposures but also high dose-rate situations like in medical radiology. Moreover, as several recent epidemiological studies point to a DDREF not significantly different of 1, the choice of a reduced value of DDREF would certainly be justifiable from a radiation protection perspective. BVS-proposal: ICRP should adopt a more precautionary approach in relation with DDREF, especially in high dose-rate situations like in medical radiology. Age and gender The differences of risks due to age and gender are hardly taken into account in the calculation of effective doses (single set of tissue weighting factors) and in the derived organ dose limitations. A way for better taking age and gender into account could be recommending the use of organ dose constraints where appropriate (for example for thyroid). BVS-proposal: ICRP should consider recommending the use of organ dose constraints taking age and gender into account where appropriate (in particular for the thyroid). NVS-proposal: Delete “called deterministic effects” in para. (48) Potential Exposures (chapter 8) Para. 318 risk constraints The background of risk constraints is not made clear enough in the ICRP’s document to implement them in practice. The generic risk of 2 x 10-4 for occupational exposure does not precisely say what risk is meant, i.e. a fatal risk per year, per lifetime, or per incident. Exposure is defined in the ICRP recommendation as a risk. Taking this into account a risk of 2 x 10-4 would correspond to a dose of 4 mSv (single exposure). Does that mean that a dose of 4 mSv is the acceptable dose for an incident? Or should this be multiplied by the probability of this incident? There is obviously a need for clarification. Proposal: give a definition of the term “risk” used in para. 318 Dosimetric Quantities (chapter 4) Absorbed dose as defined under para 95 is a non-stochastic quantity and therefore defined in a point. As such it can be determined by computation, but is not directly measurable. See ICRU33,I.B.: 'stochastic quantities can be experimentally determined, non-stochastic quantities (…) can, in principle be calculated, but (…) can be (experimentally) estimated as the average of observed values of the associated stochastic quantity' Therefore, in radiation protection mean absorbed dose (96) and averaged absorbed dose (99) is used. BVS-proposal: Change in paragraph 95 'In principle, absorbed dose is a measurable quantity and primary standards exist to determine its value. The definition of absorbed dose has the scientific rigour required for a basic physical quantity' into: 'In principle, absorbed dose is not a measurable quantity, but this definition of absorbed dose has the scientific rigour required for a basic physical quantity.' Explain the fact that, due to the fundamental stochastic nature of radiation interaction with tissue, e.g. in low doses of high LET radiation, most cells are not hit. The value of energy imparted in most individual cells is zero, but in the hit cell it will exceed the mean value by orders of magnitude. Explain the difference between stochastic quantities and non-stochastic quantities (e.g. in annex A) and its relevance for radiation protection and e.g. general medical applications at the one side and e.g. microdosimetry and specific cases of radiation therapy at the other side. The equivalent dose is a dose in a generic sense, but not in its physical sense. The unit of the equivalent dose is therefore chosen to be the sievert, and not the gray, but this is definitely not a J/kg, neither in a generic sense, nor in a physical or mathematical sense. An equivalent dose has nothing to do with a joule (J). The reason for this confusion is the choice for a dimensionless radiation weighting coefficient. Logically and mathematically correct is to choose for a dimensional radiation weighting factor while transforming the absorbed dose into an equivalent dose with the dimension of Sv/Gy: HT [Sv] = wRDT [(Sv/Gy).Gy] BVS-proposal: Change the dimensionless radiation weighting coefficient into a dimensional radiation weighting factor with the dimension of Sv/Gy. In para. 145 the special name for the collective dose quantity is proposed to be the 'man Sievert'. As radiation interactions have no human and/or gender like aspects, it is preferred to remain gender independent in the definition of units as is already the policy preferred by the Health Physics Society and by other authorities as well, and in accordance with para. 355 where the 'reference man' is replaced by the 'reference person'. BVS-proposal: Change 'man Sievert' into 'person Sievert'. To avoid aggregation of very low individual doses over extended time periods and wide geographical regions, limiting conditions need to be set in the definition of collective dose (148). BVS-proposal: Please explain and specify E1 and E2 in equation 4.12. Absorbed dose as defined under paragraph 95 is a non-stochastic quantity and therefore defined in a point. As such it can be determined by computation, but is not directly measurable. See ICRU33,I.B.: 'stochastic quantities can be experimentally determined, non-stochastic quantities (…) can, in principle be calculated, but (…) can be (experimentally) estimated as the average of observed values of the associated stochastic quantity' Therefore, in radiation protection mean absorbed dose (96) and averaged absorbed dose (99) is used. BVS-proposal: Change in paragraph 95 'In principle, absorbed dose is a measurable quantity and primary standards exist to determine its value. The definition of absorbed dose has the scientific rigour required for a basic physical quantity' into: 'In principle, absorbed dose is not a measurable quantity, but this definition of absorbed dose has the scientific rigour required for a basic physical quantity.' Explain the fact that, due to the fundamental stochastic nature of radiation interaction with tissue, e.g. in low doses of high LET radiation, most cells are not hit. The value of energy imparted in most individual cells is zero, but in the hit cell it will exceed the mean value by orders of magnitude. Explain the difference between stochastic quantities and non-stochastic quantities (e.g. in annex A) and its relevance for radiation protection and e.g. general medical applications at the one side and e.g. microdosimetry and specific cases of radiation therapy at the other side.. In para. 105 the last sentence is not very clear: 'At very high neutron energies the radiation weighting factor decreases and approaches 2 to be consistent with the wR values for neutrons and protons' BVS-proposal: At very high neutron energies the radiation weighting factor decreases and approaches 2 to be consistent with the wR values for protons' Since male and female computational phantoms are defined, it seems more logical to define also gender-specific tissue weighting factors (117-120). The effective dose would still be averaged over the genders, and thus the same end-result will appear. These gender-specific tissue weighting factors will make the calculation of E clearer, and removes the need for explaining artificially gender-averaged weighting factors. BVS-proposal: Change equation 4.5 into: . E = [ (SigmaT wTM HTM + SigmaT wTF HTF) / 2 ] The quality factor Q will not be changed, thus the change in wR e.g. for neutrons will not be reflected in the operational quantities. BVS-proposal: Include a paragraph explaining this, because this will be quite confusing for many people. It is true that Hp(3) has rarely been used, but personal dosemeters for Hp(3) are relatively easy to construct with e.g. thermoluminescent dosemeters. So this is no reason to disregard Hp(3). BVS-proposal: Delete in paragraph in 125 the last part of the sentence stating that no personal dosemeters are generally available that allow this to be measured. Conversion factors to calculate the operational quantities starting from the fundamental quantities are available. These were calculated with anthropomorphic phantoms. Although nothing changes for the operational quantities, the conversion coefficients will be changed due to the introduction of the voxel phantoms. BVS-proposal: Include a paragraph regarding the influence of this, i.e. should new conversion factors be calculated or will the difference be negligible The last three sentences of para. (133) (starting with "In the calculation ...") are very important, specifically for inhaled natural radionuclides in a matrix where radon and\or thoron do not escape from the particles. In ICRP publication 68, when calculating the dose coefficient for 226Ra, this situation has been taken into account, but later on the Commission has taken a different position. In ICRP 72, Annex B, a correction is made for the dose coefficient of 226Ra, by stating that this assumption appears to be overly cautious for 226Ra, where a substantial fraction of 222Rn decay products would be expected to escape from the lung. Many NORM materials, such as mineral sands, show a radionuclide composition where 238U or 232Th are in secular equilibrium. This implies that the radionuclides of radon do not escape from the matrix and therefore contribute to the dose coefficient when inhaled. NVS-proposal: The Commission should reformulate the last sentence of para. (133) in order to make clear for which situations the original assumption for using the dose coefficient of 226Ra, as taken in ICRP 68, is better reflecting reality. Protection of the Environment (chapter 10) It is difficult to understand, why an enlargement of the radiation protection system from a situation where the focus lies on the protection of man to the environment is really needed. The ICRP document states in para. 20 that there might be situations where there are no human beings and the environment needs protection. It would be logical that on the other hand, in areas which are densely occupied by man, as is the case at least for Middle Europe, such an enlargement of radiation protection is unnecessary. Such a statement would be helpful and it should be included in chapter 10. Proposal: include a statement that for densely populated regions the proof of a sufficient protection of humans is sufficient to guarantee also the protection of the environment The significance of the determination of doses for reference plants and animals is not adequately explained. While it is scientifically possible to perform a dose evaluation for non-human biota, dose criteria for the interpretation of the evaluation results are needed. Those dose criteria have not yet been developed in a consistent and comprehensive way for world-wide application. There is a lack of those considerations in chapter 10. Giving recommendations in the way ICRP does in this respect gives the impression that a ship starts and nobody knows where the journey will go to. Implementation (chapter 11) Para. 389 (and para. 149) In the paragraphs and chapters on the assessment of doses ICRP addresses very well the uncertainties which are necessarily involved in every model and the necessity to derive “best estimates” of model parameter values. Unfortunately the following fact for the practise of radiological protection is not adequately acknowledged by ICRP The exposure of occupationally exposed persons can be very precisely determined by individual measurement (personal dosimetry). Thus the records will show real doses which can be compared with respective constraints or limits to evaluate the system of radiological protection For the exposure of members of the public there is basically a different situation. Doses will normally not be measured but calculated on the basis of models which in general are conservative, i.e. tend to overestimate the real doses. While comparing these calculated doses with e.g. set dose constraints for members of the public they often are regarded, as if they would be measured real doses, and their conservative and statistical character is not taken into account. In consequence that leads to unjustified exaggerations of protection measures. In this context it is missed a clarification that calculated estimates of exposure cannot be treated in the same way as measured exposures, and that it is not justified to take any upper value of a calculated probability distribution of doses as an adequate value for such comparisons. Proposal: Clarify that calculated estimates of exposure should not be treated in the same way as measured exposures and give some indications how to treat these calculated estimates.


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