Draft document: Recommendations
Submitted by Bruce Heinmiller, Atomic Energy of Canada Ltd.
Commenting as an individual

The report states that dose limits for the lens of the eye, the skin, and extremities are established to prevent tissue reactions. It also states that for doses that could give rise to tissue reactions, absorbed dose should be estimated, and the appropriate RBE taken into account, and that equivalent dose and effective dose should not be used in the quantification of radiation doses in assessing treatment needs for tissue reactions. Further, values of RBE for tissue reactions caused by high-LET radiations are found to be lower than those for stochastic effects (usually much lower), and radiation weighting factors are meant to reflect stochastic-effects RBEs. With this background, I question the expression of dose limits for the tissues cited above as equivalent doses in units of mSv. It would seem that these dose limits would be more appropriately expressed as absorbed doses in units of mGy. If equivalent doses in mSv are retained because of expediency in matching to measured quantities and accounting (conservatively) for some non-unity value of RBE for high-LET radiations, then this should at least be indicated as a footnote to the tables to explain the apparent contradiction in the dose quantities used for these dose limits. If absorbed doses are adopted as suggested, then the glossary requires the corresponding change. The symbol for particle fluence in the glossary is one normally used to denote fluence rate. The third sentence in paragraph 286 is not understood. END OF COMMENTS