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ICRP: Free the Annals!

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Submitted by Dr Chris Kalman, Salus Occupational Health & Safety
   Commenting as an individual
Document 2005 ICRP Recommendation
I am grateful for the opportunity to comment on the draft 2005 Recommendations of the Commission. I am an Occupational Physician with many years experience on talking to both radiation workers, and the public about radiation issues. It is on this basis that I thought it was appropriate to raise comments. These consist of one major observation which in my view is of fundamental importance, and a few more minor observations. I would hope that the Commission would agree that the need for radiological protection to be understandable to workers and the public should be implicitly included within its fundamental aim. The need for public knowledge and information on radiation issues is now probably greater than ever, with considerations of terrorist threats being added to existing public and media profile of radiation issues.

It is a relatively simple job to provide information to the public on Commission recommendations based on deterministic and stochastic risk leading on to principles of radiation protection consisting of justification, optimisation and limitation. Clearly beyond these considerations, there are significant complexities. However, these are rarely not necessary to develop in a simple public information strategy. While those in radiation protection can undoubtedly appreciate the draft's contention that the proposed recommendations represent evolution rather than revolution, I do not believe that this will be apparent to the public who have limited knowledge of the issues. I would suggest that it is of absolutely vital importance that the Commission retains its now well established principles of justification, optimisation and limitation stating them clearly within the new recommendations, even if some of the detail later in the text amends the current systems to some degree. Currently justification appears to be documented purely in terms of medical exposure, though the benefits of radiation use does get repeated mention. Similarly, while the concept of limits remains in the body of the document, it is not explicitly stated in the section on principles.

I really feel very strongly, that the Commission has a duty to provide the basis for public and worker information, and having identified clear principles for more than 15 years, these basic principles must remain if this duty is to be maintained.

I would regard the following comments as significantly less important than the issue raised above:-

1. The document makes significant mention of safety culture which probably requires further explanation. The concept was first coined by the nuclear industry in relation to considerations of nuclear safety and avoidance of accidents, it has of course been taken over by conventional health and safety where again it is almost exclusively used in relation to actions to reduce the frequency of accidents. On this basis, it does not appear immediately appropriate to the description of reducing day to day radiation exposure, where there is no accident, and where the end point is quite clearly related to health rather than trauma. As an Occupational Physician, I believe it would be of significant advantage for the Commission to begin to lead considerations of what would rightly be called a health and safety culture.

2. Clearly, in terms of both occupational and emergency exposure, the concepts of societal or population risk are of importance. For many years, they have been important considerations in relation to justification decisions, and in relation to the identification of consequences of events. The lack of consideration of these issues in the draft recommendations is surprising. The idea of collective risk in terms of person sieverts is not an invention of health physicists, but rather a direct result of the acceptance of a linear no threshold dose response for stochastic effects. With the Commission's continued support of this hypothesis for radiation protection use, it is clear that collective dose calculations will still be carried out whether or not they are mentioned in ICRP recommendations. With this in mind, I would suggest that the Commission must retain consideration of collective dose within its text and seek to define what is and what is not appropriate use for such calculations. Similarly, since the Commission makes recommendations on exclusion levels of nuclides based on activity, similar concepts could be used to establish deminimis individual dose contributions to collective dose calculations.

3. In relation to considerations of constraints, I was surprised to see in figure 2 a dose contribution from radiology included in the summation of public dose in relation to limits. I think this is unlikely to improve understanding. It would, however, be useful to include a picture of a hospital since certainly in the UK, the majority of sites authorised to discharge are related to the practice of medicine.

4. The basic concepts of optimisation implicitly determines that different dose levels are appropriate for different activities. It is clear, therefore, that the idea of constraints can be of benefit in public understanding of the optimisation concept. Notwithstanding this, I believe the Commission could expand its recommendations significantly to enhance this understanding, and make clear what is and what is not appropriate in considerations of constraint. It is not immediately clear, why generic types of exposure should be subject to constraint rather than selecting age of plant as perhaps something of equal importance. Similarly, it is questioned whether based on these recommendations, it is appropriate to select a higher constraint because the use is perceived as being more beneficial or whether all things should be considered equally justified. Certainly in the UK Discharge Strategy Document, it is clear that nuclear and industrial discharges are to be significantly more tightly constrained than those from medical use, and indeed, it is clear that medical doses within the UK will rise as nuclear medicine use continues to expand.

In the UK, the public consultation on exemption for natural gas facilities from statutory radiation controls provides an interesting case study of the difficulties in explaining optimisation/constraint considerations to the public. It is clear that the decision to exempt was based on optimisation etc of what was achievable, though in fact the consultation made it clear that the Government considered the radiation dose involved as "no danger". The NRPB evaluation appeared to show, however, that both in terms of collective and individual dose, the estimates were greater than many discharge situations from the nuclear industry. In these nuclear industry circumstances, there was of course continued regulatory pressure for further reduction. It is therefore questionable whether there was even some grounds for complaint based on considerations of unfair competition from two industries involved in power but with very different regulatory requirements for radiation considerations.

From my point of view, it would be of great benefit for the Commission's recommendations to clarify some of the considerations raised above.

5. Finally, in terms of considerations of constraint, I note with interest the establishment of a minimum value. Since the Commission defines constraints in terms of a level of dose where action to reduce is virtually certain to be justified, it seems implicit that the Commission would wish to see optimisation of doses below 0.01 mSv. Having established the precedent that levels of radioactive material can be exempted, it would also seem sensible for the Commission to establish a level of dose from a single source which similarly could be exempted and hence the establishment of an individual dose deminimis level for radiological protection.

I hope these comments are considered useful.

Chris Kalman
Consultant Occupational Physician