Protection of the Environment under Different Exposure Situations


Draft document: Protection of the Environment under Different Exposure Situations
Submitted by Kevin Kelleher, Radiological Protection Institute of Ireland
Commenting on behalf of the organisation

Overview

The RPII is pleased to see that there has been development in the area of radiation protection of the environment in the past number of years, even if knowledge gaps do still exist.

The information on radiation protection of the environment given in the report is quite informative given the limited information available.

It would be helpful if the objectives of this publication were made clearer. A notional objective of the report is made in the Preface to the Draft Report (Page 4 Lines – 112 to 116) but it would be useful if all of the draft report’s objectives were specified clearly in the Introduction. It is not clear whether this report is meant to be just expanding on the concepts of radiation protection of the environment introduced in ICRP 108 or whether it is meant to be a practical guide related to ICRP 108. Likewise, the knowledge and data gaps associated with radiation protection of the environment should also be stated more clearly in the Introduction.

It can be difficult to comprehend the principles of Justification and Optimisation when it comes to radiation protection of the environment. It’s understandable that the principles are used in order to have a system that can operate in parallel with protection of humans but the terminology doesn’t lend itself well to radiation protection of the environment.

A lot of the concepts described in this draft report, such as RAPS, DCRL’s etc. are better explained in ICRP 108, attempting to explain them again in this draft report in different places creates confusion. Maybe it should be stated that this draft report should be read in conjunction with ICRP 108 and the need to define these concepts would no longer be necessary?

Also, it is not clear how this approach aligns itself with other approaches to protect the environment from specific pollutants or categories of pollutants. It is stated in different locations in the draft that the needs for making evaluations of the impact of radiation in the environment with regard to exposure to biota may arise for reasons that stem from a wide range of environmental management requirements. The draft also refers to the ‘ecosystem approach’ (A13) and the need to evaluate the impacts and the collective synergistic or antagonist effects of different types of pressures. This is an approach which is increasingly advocated in the field of environmental protection and ICRP indeed acknowledges this and cites examples of a wide range of international laws and treaties (section A4 and Appendix 2). Despite this, the extended ICRP system requirements (for protection of the environment under different exposure situations) as presented in this draft does not fully succeed in positioning itself in this new ‘trend’. An example of how this can be achieved is given by the OSPAR Commission and how the various strategies were recently reviewed to align them all with the ecosystem approach (See http://www.ospar.org/html_documents/ospar/html/10-03e_nea_environment_strategy.pdf)

A lot of the text in the main body of the report is spent outlining the principles of radiation protection of humans – perhaps this could be moved to an appendix at the back of the report that outlines the parallels between radiation protection of humans and radiation protection of the environment. This would make the main body of the report more concise and easier to read.

The approach for protection of the environment under different exposure situations using Reference Animals and Plants (RAPs) and Representative organisms as outlined in this draft can be a useful starting point for determining exposures to biota in any given environment. The ICRP has acknowledged that data gaps for the RAPs do exist and that in many cases much more specific data on local animals and plants may already be available for specific sites (page 50 Paragraph A78). However, it is not clear what should be done in the cases where specific data is available – should the same approach be used or should the specific data be used in determining doses to biota in specific locations?

ICRP 108 gives an outline of how doses to various Representative organisms can be determined using appropriate Dose Conversion Factors for specific radionuclides. Based on the RPII’s experience to date in radiation protection of the environment, the radionuclides listed are by no means a complete list and gaps do exist. This has been acknowledged throughout the Draft Report but additional guidance on what to do in the event of such occurrences would be useful.

The section of the report on the Practical Aspects (ANNEX A) does go into greater detail on the subject of Radiation Protection of the Environment but still lacks information on the practical application of this concept. In addition, parts of the Annex are weakened by the lack of available data. A lot of detail is given, even though very little information is known about certain aspects of radiation protection of the environment. With this in mind perhaps this detail is a little premature.

The data gaps that exist in the area of radiological protection of the environment have been acknowledged but, given the lack of  data, a commitment to add to the available databases or co-ordinate the compilation of available data in the future would be welcomed.

The draft report refers to the RAPs using their “common name” and Section A.2.2. states that a more thorough definition is available in ICRP 108. However, it would be useful if the taxonomic family names were referred to in the current draft as using the “common names” alone could lead to some confusion i.e. Reference Deer = A Large Terrestrial Mammal, Reference Rat = A Small Terrestrial Mammal, An Aquatic Bird = Reference Duck etc. For example, this could lead to confusion in the marine environment when choosing the reference deer as a RAP for a marine mammal such as a dolphin or whale.

The RAPs chosen for use in this draft are based on studies in temperate climates and are to be applied globally (Page 36 Paragraph A29)– this is an important limitation which should be stated clearly at the beginning of the draft report.

Further clarity (or more practical guidance) on the approach to use DCRLs for planned, existing and emergency exposure situations are needed, particularly on how the DCRLs relate to ERLs and the severe effects level.

A schematic outlining how DCRL bands, ERLs, background and severe effects levels relate to each other would be useful.

The legislation associated with protection of the environment referenced in this report needs to be reviewed for currency and relevancy as some of it may be out-of-date or superseded.

Specific Comments

Page 5 Paragraph (c) line 166[1]

In this draft, is the word ‘biota’ equivalent to ‘non-human organisms’ (as per paragraph (a) page 5 line 154) and if it is the case, what does ‘non-human biota’ mean? Or does ‘biota’ include ALL animals and plants (as per definition of environmental radiation protection (page 8 line 297), in which case humans are part of the biota? Page 11 paragraph (5) line 398 states ‘... non-human species – referred to in this report simply as ‘biota’.’

Page 5 Paragraph (d) line 177 and Page 18 Paragraph (37) line 672 

These paragraphs use the term “environmental exposure of significance” but it is not clear what an environmental exposure of significance is.  Page 24 Paragraph (51) does state that “...consideration of the use of Environmental Reference Levels would apply mainly to major nuclear installations...” etc. Is this what the Commission regards as an environmental exposure of significance?

Page 6 Paragraph (e) line 199 and Page 19 Paragraph (39) line 709

These paragraphs state that an appropriate band of dose rates “at least one or more orders of magnitude above the DCRL”. This statement is a bit vague and so is the statement on Page 43 lines 1615 and 1616 relating to severe effects: “These might typically be dose rates likely to result in total reproductive failure”, which could be interpreted as conflicting with the statement above as, based on the information available in ICRP 108, total reproductive failure is not evident in the reference animals and plants one or more orders of magnitude above the DCRL.

Page 6 Paragraph (f) line 213

“For existing exposure situations, if the dose rate is above the relevant DCRL bands, the ICRP recommends that the level of ambition for optimisation would be to reduce exposure levels to within the relevant DCRL bands”

The terminology “level of ambition for optimisation” is difficult to understand.  Is this similar to the Diagnostic Reference Level used in medical exposure situations (Council Directive 97/43/Euratom of 30 June 1997, http://ec.europa.eu/energy/nuclear/radioprotection/doc/legislation/9743_en.pdf)?

Page 6 Paragraph (g) line 221

The sentence ‘... the necessity for dose limits to ensure equity in the application of optimisation for human exposures does not clearly exist in the optimisation of protection of the environment’ would need some explanation as it is not clear what this actually means.

Page 7 Paragraph (h) line 239

Is there a need for the word ‘generally’?

Page 7 Paragraph (h) line 240

Referring to the ‘future use and value’ of the environment might not be the best way of approaching the protection of the environment. These terms have too strong ‘mercantile’ connotations which might be seen as being contrary to the spirit of environmental protection.

Page 7 Paragraph (i) line 250  

“some forms of morbidity”, this may need more explanation as to why the Commission is only focussed on some forms of morbidity. A reference from ICRP 108 page 71 stating “making it more difficult for them to survive in a wild environment” would be sufficient.

Page 7 Paragraph (j) line 257

“It is also necessary to identify Representative Organisms relevant to each evaluation”. Is there any guidance on how to identify representative organisms relevant to each evaluation?

Page 8 line 290

The word ‘practice’ has specific meaning with regard to the current EU BSS Directive. Does this have the same meaning here?

Page 10 Paragraph (3) line 373           

States that “environmental exposures....may need to be assessed” but does not outline any criteria to determine whether an assessment is necessary.

Page 12 Paragraph (10) line 430        

What is ICRP’s advice for the estimation of the natural background radiation (this is referred to in this paragraph as well as in tables in Appendix 1)? Should it be based on local measurements (what type of measurements), on UNSCEAR average values, on IAEA guidance documents or any other information? Some attempt has been made at defining the natural background dose rates in various environments in ICRP 108, perhaps this could be referenced here.

Page 13 Paragraph 17 line 466

“Environmental resources... of human value”. These are often now referred to as ‘environmental medium ecosystem services’.

Page 13 Paragraph 17 line 476

“Environmental media are therefore considered by the Commission as pathways of exposure, whereas the recommendations relating to protection are derived from an understanding of effects in, and the sensitivity of, the organisms living in the environment.”

This may not be the case, all environmental media have an intrinsic value in their own right and soil in particular is a far more complex environmental media compared to air or groundwater.  Soil could be considered both a receptor and a pathway.

Page 14 Paragraph (19) line 490, and Page 16 Paragraph (30) line 581

Exposure types and categories have been clearly defined but what defines an exposure ‘situation’?

Page 14 Paragraph (23) line 516

Why is cost only considered for emergency and existing exposures and not for planning exposures?

Page 16 Paragraph (32) line 606

Is it possible to expand on the following statement ‘In the Commission’s view it would be unacceptable to plan activities so that resulting doses are above the predefined constraint level; although should this occur, it should not be formally regarded as a regulatory infraction’. Should it be understood as ‘it is not an infraction to exceed a dose constraint as long as it can be demonstrated that the practice itself is justified and the overall risk is minimal’ simply because dose constraints apply to single sources?

Page 19 Paragraph 38 line 686 and Figure 3 line 694      

For planned exposure situations, it is suggested that the ERL be set at a level below the lower boundary of the DCRL in order to take into consideration possible cumulative impacts. This is also stated in the title for Figure 3 (Lines 694 – 696). It is not clear whether the ERL should ALWAYS be set at a level below the relevant DCRL regardless of whether other sources or historic sources are present in the environment or whether it should be below the DCRL ONLY when other sources or historic sources are present in the same location.

Page 19 Paragraph 39 line 708

“the probability of severe effects occurring...” : are these immediate effects or over some timescale?  The timescale may vary for organisms of different complexities.

Page 22 Paragraph 43 line764 

The dose to the Representative Person is defined as the dose that is representative of the more highly exposed individuals in the relevant population but this is not the case for Representative Organisms. The reasons for this are explained later in the document (Page 38 Paragraph A36) but further clarification may be useful here. In addition, some explanation as to why the focus is not on the single Representative Organism most sensitive to exposure in a particular environment would also be helpful.

Page 22 line 782   

What does ‘evaluation’ mean in this draft? It might be relevant to define this term in the Glossary. Also, if it is equivalent to assessment, it might be better to use the word assessment simply because it is used more in radiation protection than ‘evaluation’.

Page 24 Paragraph 51 line 859

The statement “the Commission would expect that consideration of the use of Environmental Reference Levels would apply mainly to major nuclear installations; to major industrial or other activities generating waste or discharges with significant concentrations of radionuclides, even if volumes are small; to major activities generating large volumes of waste, such as the mining and milling of radioactive ores; or to small environmental areas that were subject to the input of radionuclides from several sources” is not strong enough and doesn’t specifically set out when DCRLs and ERLs should be used. Does this paragraph cover all relevant environmental exposure situations? It could be interpreted as only those industries directly associated with nuclear power as opposed to other industries that also discharge radioactivity into the environment e.g. NORM industries.

Page 27 Paragraph (56) line 937

It is stated here that ‘these values (i.e. DCRLs) are not limits, and are not intended to be used in that manner’. This is a very important statement which should appear much earlier on, including in the Summary.

Page 35 Paragraph (A24) line 1287   

The words used in the statement that reads ‘Quite clearly, apart from the first (objective), this is collectively a daunting and virtually impossible task. The range of biota is immense, and the effects of radiation on them, at different stages in their life cycles, are not only unknown but unknowable’ are quite strong. It might be beneficial to try and re-phrase this statement.

Page 36 Paragraph A29 line 1350

The RAP system is limited to temperate areas, and so is not global in its application

Page 37 Paragraph A29 line 1353      

“With regard to typical farm animals - primarily large mammals that live essentially in a human environment – it was considered that the use of the human animal itself was probably sufficient for such managed environmental or ecological situations.” It is not clear what a “human animal” is – does this mean a Representative Person and if so is this the best approach?

Page 37 Paragraph A30

‘This publication’ refers to which one?

Page 40 Paragraph A40 line 1481      

“Interest in the potential environmental impact of radionuclides released into the environment is only likely to be of concern in relation to large nuclear facilities”. I don’t think this is the case. Discharges of radionuclides from any facility are likely to be of concern to stakeholders.

Page 42 Paragraph A49 line 1578 and Page 52 Paragraph A87 line 2023

“...restricting environmental exposures...” and “‘...compliance with any ERL...’. The words “restricting” and “compliance” imply some sort of legal requirement. Is this the intended meaning? [2]

Page 45 Paragraph A58 line 1714

Repeating the explanation of what a Representative Organism is or what RAPs are is confusing. Also, which one corresponds to ‘sub-sets of typical organisms’?

Page 46 to 48 Sections A.4.2 to A.4.5

There is an overall sense that these issues (differences between Representative Organisms and RAPs) and how ICRP recommend we deal with them, although described in some details in the draft, relies on data with a lot of gaps. Therefore there is a sense that too much is actually said about issues that are actually not well understood.  The concepts of RAPs and Representative Organisms are repeated a number of times in this report; it may be more useful to outline these concepts early in the draft report and avoid doing so again thus making the draft report more concise and clear. There is also a lack of guidance as to how these issues could be explained and communicated to stakeholders.

Page 47 Paragraph A67 line 1790      

The statement “For a given mass and energy, the external exposure is highest for a shape with the lowest surface–volume-ratio, whereas external exposure increases with increasing surface-volume ratio” is contradictory.

Page 48 Paragraph A71

It is not clear why this paragraph is here and how it relates to what is said before.

Page 52 Paragraph A85

Is this paragraph really dealing with ‘Stakeholder involvement’? Suggest including it in the next Section (A.5.4.) instead.

Pages 57 to 59

The tables of Dose Rates and Effects in Appendix 1 taken from ICRP 108 require more clarity in the context of this report if they are to be included. Terms such as “No positive ‘effect’ information” (Reference Frog) and “Effects unlikely” (Reference Earthworm) are very vague.

Page 60 Line 2912

An explanation for why this is the case would be useful.

Pages 61 and 62

Appendices 2 and 3 outline examples of National and International Environmental Laws, Treaties and Legislation. This selection appears to be incomplete and the basis for inclusion is not clear which undermines its relevance. These appendices should be reviewed and updated to include all relevant legislation or maybe it would be more appropriate to remove them altogether. 

Typographical/Editorial Comments:

Page 5 Paragraph (d) line 187, and Page 19 Paragraph (38) line 685

Environmental Reference Level (ERL) should be in italic characters to be consistent with DCRLs

Page 6 Paragraph (h) line 236 

“intsdcavernational” agreements?

Page 8 line 303      

space between “practices” and “that”

Page 10 Paragraph 1 line 358  

Add a reference to ICRP 91

Page 10 Paragraph 1       

Consistency in references e.g. ICRP 108 (2008) or ICRP 2008 etc.

Page 10 Paragraph (3) line 371

The word “receptors” instead of “targets” should be used

Page 10 Paragraph 4, Page 37 Paragraph A30 and Page 43 Paragraph A54:

These paragraphs reference ICRP 114, 2011 but this reference does not appear in the references for the report (Page 28) or Annex A (Page 54)

Page 11 Paragraph 6       

Suggest rewriting this paragraph to improve readability. As a single sentence paragraph, it is quite difficult to follow.

Page 12 Paragraph 9 line 428  

Is the verb ‘avoid’ the most appropriate here? Is ‘prevent’ more suitable?

Page 13 Paragraph 15 line 458

Is it necessary to include the word “additional” in this statement?

Page 17 Figure 1

Is the y-axis unit mSv per year in effective dose?

Page 18 Figure 2

Is the y-axis unit mGy/d in absorbed dose rate?

Page 20 Paragraph 41 and Figure 4   

It is not clear how figure 4 relates to line 731. It might be more suitable to reference Figure 4 in Paragraph 39.

Page 24 Paragraph 52 line 877

“Future” instead of “Furure”

Page 30 Paragraph A4 line 1033         

Should read Appendix 2 instead of Annex A

Page 30 Paragraph A3:   

References CEC 1996, 1992, 2000 and 1985 should be EC 1996, 1992, 2000

Page 40 Paragraph A40 line 1487

Would recommend including national obligations in Line 1487

Page 41 Paragraph A44 line 1524      

This is the first time Relative Biological Effectiveness is mentioned, the meaning of this should be defined here or in the Glossary.

Page 41 Paragraph A44 line 1530      

DCRL instead of DCL

Page 41 Paragraph A44 line 1540      

The data is in Table 2.1 of Chapter 2 in ICRP 108 and in Appendix 4 of this document.

Page 43 Paragraph A52 line 1618

Appendix 1 instead of Annex 4.

Page 45 Paragraph A58 line 1712

Section A2.4 instead of Section 2.4

Page 45 Paragraph A58 line 1719      

No reference exists for EA 2009 should instead be (Environment Agency, 2009)

Page 46 Paragraph A60 line 1747      

Annex A instead of Appendix A

Page 47 Paragraph A62 line 1766      

Appendix 4 instead of Annex 3

Page 47 Paragraph A64 line 1779      

Include reference to ICRP 108

Page 47 Paragraph (A68) line 1800

This is the first time the term ‘LET’ appears in the draft. A definition in the Glossary would be helpful.

Page 48 Paragraph A70 line 1819      

Remove full stop.

Page 54 line 2084

Replace ‘DC Dg Env.’ with EC DG Env

Page 54 line 2098

Check the authors list: Higley K. A. is mentioned twice and 2012 appears in the middle of the list of authors, not at the end.

Page 8 GLOSSARY

It would be useful to include definitions for:  Dose Limit, Dose Constraint, ERL, Evaluation, LET, Natural Environment, RBE and Residual Dose.

 



[1] Also Page 10 Paragraph (3) line 371, Page 13 Paragraph (17) line 475, Page 137 Paragraph (36) line 646, Page 20 Paragraph (41) line 723, Page 43 Paragraph (A53) line 1629

[2] ICRP 108 in its Guest Editorial (p5) states: ‘The recommended system, which has been adopted by the Commission, is not intended to set regulatory standards’.

















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