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


Draft 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
Submitted by Bertrand Thériault, Canadian Nuclear Safety Commission
Commenting on behalf of the organisation

General comment that this is an excellent reference for radiological risks at specific tissue and organ level. 

1.       In the Executive summary and main text there are numerous instances of where treatment for specific types of radiation damage is offered.  While this information is undoubtedly useful, it is outside the stated scope of this document.  Since the document is very large, suggest that the material be referenced to another document.

2.       Line 304-306 note that growing bone is among the most radiosensitive of all tissues and 25 Gy in 2 Gy factions is often suggested as a critical threshold”.  This is a very high dose and there are many tissues much more radiosensitive than this. Suggest the text be checked for possible transcription error.

3.       There are a number of references to the term “low dose”.  For example line 327 in the Executive summary states 1 to 2 mSv as low dose radiation, but line 1322 states “low dose” as < 0.5 Gy and low dose rates of <0.2 Gy min-1

4.       Line 3212 makes a general statement that the RBE of neutrons increases with decreasing neutron energy.  There should be a qualifier here to account for the increasing RBE of neutrons with increasing neutron energy below 1 MeV.  (and to be consistent with the ICRP’s weighting factor  graph for neutrons).

5.       The review of the response of tissues and organs to radiation (Chapter 2) is excellent. It is very comprehensive, providing a ready reference to radiation effects on a tissue and organ basis.  It is suggested that a table be included that summarizes the tissues, the identified effects and the lowest dose that shows these effects.


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