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Submitted by Nobuyuki Hamada, Radiation Safety Research Center, Central Research Institute of Electric Power Industry (CRIEPI)
   Commenting on behalf of the organisation
Document Early and late effects of radiation in normal tissues and organs: threshold doses for tissue reactions and other non-cancer effects of radiation in a radiation protection context
 

I'm herewith sending the comments on  Eye (Sections 2.6 and 4.7) on behalf of Radiation Safety Research Center, CRIEPI. 


(1) Regarding epidemiological and biological findings for chronic exposure situations, consistent evidence has not accumulated (Paragraphs 677-679). Judgment about dose thresholds for acute or fractionated exposures should not be used for extrapolation to chronic exposure situations.


    As described in the draft (Paragraph 679), the uncertainties about epidemiological findings make it difficult to judge dose thresholds for chronic exposures, unlike the case for acute, or protracted and fractionated exposures. There is also no mechanistic evidence that effects of low-dose-rate radiation accumulate throughout the life course. In such situations, extrapolation is inappropriate.


 


(2) Conclusions should be drawn each for detectable lens opacities and vision-impairing cataracts (Paragraphs 678-680).


    Different threshold values have been given for detectable lens opacities and vision-impairing cataracts so far, but this draft provided the same value for both of them. Until the direct mechanistic evidence that all minor lens opacities progress with time to cataracts gets available, dose thresholds for detectable lens opacities and vision-impairing cataracts should be considered separately.


 


(3) Evidence used to draw critical conclusions should come from peer-reviewed original articles.


    In several conclusive phrases, there have been citations of non-peer-reviewed articles, inconsistent descriptions in the draft and references, and not enough supportive evidence. Proper referencing or deletion of related descriptions should be done.


(a) Citations of non-peer-reviewed articles


    Meeting reports, extended abstracts and submitted manuscripts have been referenced (e.g., Paragraph 294 and 675).


(b) Inconsistent descriptions in the draft and references


    Concerning Paragraph 294, dose values shown are 10 and 50 mGy in the reference, but are 100 and 500 mGy in the draft. Also, figure was not available in the reference.


(c) Enough evidence supporting the following hypotheses/assumptions has not been provided.


    [1] The latency of such changes is inversely related to dose (Paragraph 235). [2] Radiation cataracts develop in a characteristic sequential and progressive fashion (Paragraph 241). [3] Detectable lens opacities, given enough time, will progress to visual disability (Paragraph 248).