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Submitted by Stephen Evans, IPEM (The Institute of Physics and Engineering in Medicine)
   Commenting on behalf of the organisation
Document Recommendations
 
GENERAL COMMENTS

IPEM welcomes the opportunity to comment on these draft recommendations which, overall, we found to read well, be clearly delivered and nicely explained although there did seem to be unnecessary repetition in places. In some parts it seemed to go to unnecessary lengths to explain the rationale behind some of its recommendations, for instance, those concerned with controllable doses and trivial doses, while in some other parts, where only minor changes were presented, it only briefly touched upon the rationale used. At the end we were left thinking that, although a number of new issues have been introduced, particularly on security and natural sources, overall the document did not have a great deal of substantive change since its predecessor ICRP 60 in 1990. Because we note the document contains relatively minor shifts in radiological protection principles rather than ground breaking initiatives is not meant to act as a criticism but merely an observation. Indeed, we broadly welcome the fact that this means the recommendations should not result in changes to existing regulations (as you indicate in paragraph (12)) that have been based on ICRP 60.

We did note however, that there are several references to dose constraints being set nationally. This would require a change in national legislation - contrary to paragraph (12). We thought it would be better to be clear whether constraints are to be set nationally or by individual employers - perhaps with some professional body guidance.

The following response from IPEM will largely discuss those aspects of particular relevance in the medical field.

1. INTRODUCTION

(18) This paragraph needs to explain what it means by systems of assessments.

2. THE AIMS AND SCOPE OF THE RECOMMENDATIONS

(30) and (33) These paragraphs do not help to clarify ALARA versus dose constraints. The use of constraints still needs clarification. We felt that one needs to read the whole document to gradually gather that planned use of a source should not be such that the planned source constraint is exceeded, but ALARA still prevails so exposures need optimisation below the constraint level too. A better explanation would be helpful. Perhaps a clear definition of constraints is needed up front.

(45) We thought the scope and exclusion/intervention is dealt with satisfactorily, but the 1st bullet point here is unclear. If a source has an attributable risk equivalent to 10uSv per annum after controls have been put in place, is it still exempt, or does the 10uSv just refer to sources before control?

(40) If the use of the term ‘practice’ is thought to be confusing when used in the medical field we suggest that the term ‘radiological practice’ is used throughout not only for medical applications.

(44) The example of 40K uptake being an example of an uncontrollable exposure is not strictly true. Although the uptake is related to an individual’s ability to absorb 40K it can be affected by releases of 40K into the environment as a consequence of mans activities.

4. DOSIMETRIC QUANTITIES

(97) It should be noted that the dose limit on local skin dose takes into account the exposure of high as well as low-penetrating radiation.

TABLE 3 and Fig 1. – We felt that the use of a continuous function for neutrons seems unnecessarily complicated and implies greater accuracy than is the case. Consequently, the document seems to place more importance on neutron exposures compared with other types of exposures. The step function used previously would still seem most appropriate for the new quantities.

(114) We thought the splitting rule should be explained if it needs to be mentioned.

(132) Individual dosimeters measure Hp(07) as well as Hp(10).

(136) to (138) The comments in this section are welcomed regarding the restriction of the use of effective dose and planning exposure of patients being based on absorbed dose or equivalent dose.

5. THE SYSTEM OF RADIOLOGICAL PROTECTION OF HUMANS

(161) We thought the warning given here about the operators and regulators use of dose constraints is very illuminating and potentially concerning. This warning could largely be avoided if the regulator’s role was to ensure dose limits are not exceeded by the operator through the operator’s (not regulator’s) use of dose constraints.

This paragraph gives the example of X-ray equipment in hospitals as a source to which a constraint could be applied. This is a good example provided it is clear that the constraint applies to the occupational use of such equipment and does not apply to patient exposure. For purposes of clarity we thought an alternative example might be better (e.g. industrial radiography or baggage scanner) which did not have this potential ambiguity.

(170) We thought the definition of a radiation worker as one with duties in relation to occupational radiological protection can be misinterpreted. For example, a medical doctor may be a radiation worker but (wrongly) consider this paragraph to relate only to those in the radiation protection section who have specific duties in relation to occupational radiological protection.

(171) and (395) Both these paragraphs imply that there should be a distinction between employees who work in designated areas and those who are not occupationally exposed - UK legislation does not make this distinction when applying dose limits, although in practice our application of dose constraints does recognise that e.g. admin staff should be members of the public. We felt that trying to carry through the recommendations into law would be fraught with difficulty, especially in our (medical) sector where most of our "radiation workers" do get less than 1mSv per annum.

(175) This paragraph dose not explain the difference (if any) between a representative individual and a member of the critical group.

(180) The doses associated with the inadvertent ingestion of radionuclides in breast milk could, under certain circumstances, be significantly more than implied here.

(186) We felt that the statement that dose limits do not apply to existing situations may be misinterpreted if the reader is unfamiliar with this term (which is not widely used in the medical sector). We believe the use of the term ‘existing situation’ is unfortunate and an alternative term is recommended. Perhaps the use of the terms controlled and uncontrolled situations instead of planned and existing situations would be better.

(191) Justification can be carried out in the UK by appropriately trained ‘other health professionals’ as well as by medical practitioners and the paragraph should indicate this broader scope.

(201) The last sentence here should refer to emergency or existing exposure situations only.

TABLE 4 – The table should reflect the fact that a dose constraint of less than 1 mSv may be appropriate for radiation workers as well as members of the public.

6. MEDICAL EXPOSURE OF PATIENTS

Overall this section is broadly supported and we thought it was clearly presented. We particularly welcome the statements in paragraphs 245 and 246.

(250) See (191) above. Likewise, a request may be made (in the UK) by an ‘other health professional’ not only a physician.

This paragraph implies individual justification is not necessary for diagnostic procedures which are not complex. Although we do not have a problem with this approach, if this is the Commission's intention it should be stated more clearly and it would be helpful to define what is meant by complex.

(254) Diagnostic reference levels could be set by professional bodies allied to the medical field not only by professional medical bodies.

(264) Although we agree that the inclusion of pregnant females in biomedical research should normally be discouraged, there may be instances where the research is only valid if the subject is pregnant. Whilst extra consideration of risk to the foetus should be expected, such research should be heavily scrutinised but not necessarily discouraged.

(266) The second statement needs revising to make clear that the exposure of families and friends of patients discharged from hospital may not be informed or consented as implied.

(271) Public exposures may result from wastes discharged outside nuclear medicine departments (e.g. patients on wards).

There is some confusion and ambiguity about what constitutes a nuclear medicine patient. Consistency would be better achieved by using the terms diagnostic nuclear medicine or therapeutic nuclear medicine.

11. IMPLEMENTATION OF THE COMMISSION’S RECOMMENDATIONS

The implementation of the recommendations in this chapter is valuable. Paragraphs 379, 383, and 385 are particularly helpful.

(387) Supervising physician needs to be defined.

In the UK only classified radiation workers would be seen by a physician. This amounts to relatively few people in the medical sector. Pregnant workers would usually speak to their Radiation Protection Adviser or head of their radiation protection service for advice on any necessary changes to their working arrangements rather than a physician.