2005 ICRP Recommendation

Draft document: 2005 ICRP Recommendation
Submitted by Eduardo Scarnichia, CNEA
Commenting as an individual

pag. 32: Table 6: Why the detriment for the whole population is 6.5 instead of 6.4, when the values for lethality and heritable from table A1 are 6.19 and 0.19? pag. 43: Table 7: 0.01 mSv/y = 0.00114 µSv/h (or 0.005 µSv/h in 2000 h/y) is not an easily measurable doserate. I understand that a minimum value of any constraint must be measurable one (not only assessed). This is a level that only is controllable if the dose can be assessed, but if you don’t know and you can’t measure it is clearly not controllable. Pag. 56: (226): “… insurance companies may require individuals to receive medical exposures. … and national authorities should use higher values” This is, for me, a not justifiable practice; which the national authorities should not allow. Pag. 57: (232): “… If this is not possible, the only available action is to make all reasonable reduction in the probability of the event occurring. …” This sentence is in conflict with "...The focus of the effort is usually upon prevention of the undesirable scenarios or sequences which could lead to an exposure." Which is correct: the reduction in the probability comes first, at the design phase. If the "undesirable event does occur" It is already late to reduce their probability of occurrence. Pag. 61: (247): To be coherent “…by preventing the occurrence of deterministic effects” must be replaced … by preventing the occurrence of tissue reactions… Although, I prefer the word deterministic. The same at (B10). pag. 70: (A30) Conceptually is better to write "qT=KT+(1-KT)*qmin", which is mathematically the same. pag. 72, Table A1: a) The values in column 4 does not correspond with the footnote formula. For Breast the formula gives 66 not 67, for ovary 11 not 10, for Thyroid 5 not 7. The last one, at least, is not a rounding effect. b) If the qmin correction was not applied to skin, Why Lethality adjusted nominal risk is 4 instead of 2? c) Relative cancer free life lost in column 5 is called "Relative life lost", in (A10), or is not explained or mentioned in the text? d) In the footnote formula q replaces Kt of page 70. It would be better to put the same symbol in both. e) The formula in the footnote "R* q +R*(1- q)*(( 1 – qmin) q + qmin)", gives the impression to be wrong. This equation can be written as 2*R*q*(1-qmin)+R*qmin-R*q^2*(1-qmin), which gives approximately 2*R*q when qmin=0 and q<<1. This explains item b) on this page. The correct formula, for me, is R*q+R*(1-q)*qmin, or R*qT, which gives R*q as it should be. The average discrepancy in Lethality adjusted nominal risk , from the two formulas, is around 30%, with a maximum of 100% in the skin's case. Pag. 73: a) (A39) “The detriment of thyroid cancer was increased to 0.05 to take account of the concentration of cancer risk in childhood …”. The values of relative detriment, given in Table A1, were not already averaged over both genders and all ages? If it is so, why over-emphasize the thyroid risk? Otherwise, Would not be necessary to correct the values for breast, leukemia, etc.? b) (A40) “… these values did not diverge from the relative detriments of Table A1 by more than around twofold.” For each tissue in the remainder the factor is 2.56, which is around three-fold. (0.259 – 0.03 from brain, kidneys and salivary glands = 0.256, with an average weight per tissue of 0.018 instead of 0.007). In the thyroid case, the divergence is 3.33 refered to a relative detriment of 0.015 (Table A1), or 4.7 if the correct number from the footnote formula is used, or 5 using the R*qT formula.