Thank you for the opportunity to comment on the draft ICRP recommendations for the protection of individuals living in long term contaminated territories after a nuclear accident or radiation emergency. The following comments are offered by the UK Ministry of Defence’s Directorate of Safety and Claims.
Although much of what is in the draft is already available in other publications, the document is extremely useful as it pulls together this disparate information in a concise and logical way. The descriptions of past accidents and the associated countermeasures to protect the public are also extremely valuable as they allow a comparison between theory and practice. This combination makes the document of interest to a wider range of readers and increases its readability. Given this, the following comments mainly relate to a small number of areas of potential concern. The most significant relate to the need for increased transparency and justification for the recommendations relating to “1 to 20 mSv” in Paragraph 46 or to the “close to or equal to 1 mSv/y” mentioned in Paragraph 48. Given other concerns about the need for optimisation of all risks to public health, it would seem reasonable for the 1mSv/y level to be seen as a long term objective and for this to be made clear within the recommendations.
One issue is that the draft does not contain sufficient emphasis on the need for a very high level of flexibility when setting priorities for dealing with the complex and varied hazards that may exist after accidents, emergencies or military operations that affect the public. Although there is some acknowledgement of the complexity of these situations (in Paragraphs 5, 9, 17, 25 and 52), the extent to which radiation-related risks have been balanced against other risks in formulating these recommendations is unclear. This is most important if the document is to apply in situations where there is civil unrest or widespread social disruption. The concern is that the document in its present form could be cited/used as justification for giving an inappropriate degree of importance to radiation hazards over other risks. It is suggested that references to these other risks and their relative importance in different scenarios might be appropriate in Paragraphs 4, 5, 7, 42.
A related issue is that there should be more emphasis on the fact that it may be some considerable time before it will be practicable or justifiable for some of these recommendations to be fully implemented. This is because optimisation of the protection of the public needs to consider all risks and there will almost certainly risks that are more immediate and possibly life-threatening than radiation exposure. It is believed that there should be more emphasis on the fact that the recommendations represent long-term objectives and that the time taken for implementation of the recommendations will be highly dependent on the political and social conditions in the affected area and in the wider international community. This is particularly important when for past military or industrial activities. At the most basic level, some additional clarification or explanation of what is meant by “long-term” and “normal” would seem useful in Chapter 1.
As might be expected, the document relies heavily on experience gained following the accident at Chernobyl and this is acknowledged in the Preface. However the extent to which any other scenarios have been considered or addressed is not at all clear as the remainder of the publication seems to focus almost exclusively on this scenario. This seems inconsistent with the stated objective of the guidance being generic.
The final issue relates to whether radiation protection criteria for this type of event should be based on annual or lifetime exposure and whether references to Publication 103 (in Paragraphs 15, 35, 46 and 51) are valid for situations, such as cases of severe social disruption, where the balance of risks and benefits may be different from those in what might be considered in “normal life” – ie the use of radioactive materials in stable societies in peacetime. The rate of dose accumulation will be dependent on the specific exposure conditions and may be approximately linear, but, to allow for the fact that annual doses would be expected to decrease over time (due to weathering) even if no countermeasures were taken, it would seem more logical for a lifetime rather than an annual benchmark figure to be used when considering the overall optimisation of public protection. This would also seem more consistent with the view (in Paragraph 34) that “what is at stake is the long term”. In cases of civil unrest or military conflict, the risk from unexploded ordnance and the need for safe water and food and control of communicable diseases will be of far greater significance than they would be in “normal life”. At the most basic level, there does not seem to be a particularly robust justification, indeed some might say little or no justification, for the recommendations relating to “1 to 20 mSv” in Paragraph 46 or to the “close to or equal to 1 mSv/y” mentioned in Paragraph 48. It may be that such justification exists within the references, but, if this is the case, some more detailed summary is at least required so that the document can “stand alone”.
On an editorial point, there is a considerable degree of repetition within different chapters. This does emphasise very important points relating to “stakeholder involvement” and the provision of appropriate information allows individual chapters to “stand alone”, but, given the relatively small size of the document, it also creates a degree of irritation that detracts attention from these important messages. Indeed, clarity might be improved by shortening the document via the deletion of some repeated text.
(5) As discussed above, there should be some reference to the presence of risks other than those arising from radiation exposure and of the need to provide optimised protection against all potential risks.
(17) This seems to suggest that ICRP consider atmospheric nuclear weapons testing to be “unfortunate”. Is this correct?
(19) and (28) Should “minimising any potential health consequences” be added to phrases such as “improve their living conditions”, “enhancing the quality of life” and “living conditions” or are these phrases assumed to encompass the health issues?
(24) For consistency, the second sentence should acknowledge the possible existence of an intermediate phase as mentioned in Paragraphs 4 and 44. Also, shouldn’t decisions on occupation of radioactively contaminated land be “preceded” rather than “accompanied” by the setting of radiation protection criteria?
(33), (60) and (65) The benefits of allowing an affected or concerned population to carry out their own monitoring are well known. However, the practicability of this is queried and the risk of public concern from “false-positives” and the risk to public health from complacency arising from contamination not being detected from monitoring being carried out incorrectly needs to be addressed. At the very least the need for a quality assurance programme could be mentioned.
(37) and (39) There seems to be a conflict within these paragraphs. One states “the best option is not necessarily the one with the lowest dose” and the other that “continuous efforts need to be made to reduce all exposures with time”. Paragraph 40 also implies an ongoing need to “further improve the situation”.
(39) Should the possibility of increased doses through changes in habits or land use over time be mentioned?
(48) This seems to assume that the optimum solution will be to “reduce exposures to a level comparable to those in normal situations” in all cases. There is also the apparent inconsistency noted above with regard to Paragraphs 37, 39 and 40.
(54), (55) and (56) These recommendations seem to be based on the assumption that whole body counting will allow the processing of large numbers of individuals with an acceptable detection sensitivity within what most might consider to be a “reasonable” timescale. The possibility of bioassay, as in the case of contamination arising from the poisoning of Alexander Litvinenko, also needs to be considered. The reality would appear to be that it will sometimes be more practicable for the exposure pathways to be monitored first or for there to be some combination of individual and environmental monitoring?
(60) and (74) The importance of health surveillance seems somewhat over-stated in view of the statistical limitations described in Annex C and the practical difficulties of carrying out scientifically robust epidemiological work in countries which are less well-developed or have been subject to social disruption. The risk is that health surveillance may produce inconclusive results and consume resources that might be used to greater benefit elsewhere. However there is a (rather oblique) reference to these issues in Paragraph 78.