Dosimetric quantities

Draft document: Dosimetric quantities
Submitted by Keiji ODA, Committee on International Issues, Japan Health Physics Society
Commenting on behalf of the organisation

We evaluate the document to be acceptable as a whole, since circumstances and aim of the document were clearly stated, Committee 2 tried to establish a system for radiation protection dosimetry referring to problems about radiation quantities defined in the past, and most expressions we pointed out against the previous draft have been revised. There remain, however, several expressions to be discussed. 1. gRBE weighted doseh in 4th paragraph on page 8 We consider that a definition of new quantities should be avoided for establishing a simple, comprehensive dosimetric system. We agree on a proposal that the unit of the protection quantity for tissue reactions should not be in Sv. But another problem is brought about by use of RBE weighted dose. The last draft contained an idea of the name the unit of Gy-Eq. In order not to repeat the same and fruitless discussion in future, the details of discussions should be stated in this document. 2. gRadiation weighted doseh in 2nd paragraph on page 14 The name gequivalent doseh introduced in ICRP60 was replaced by gradiation weighted doseh in this document. If RBE weighted dose is used to be a protection quantity for tissue reactions, equivalent dose appears only on the way to derivation of effective dose. Is this quantity really required to radiation protection purpose ? 3. Radiation weighting factor neutrons in 4th paragraph on page 25 ICRP60 defined a step function for radiation weighting factor for neutrons in order to avoid misunderstanding that the factor does not have such a high accuracy as is expected. The reason why a continuous function replaces it in this document should be stated more clearly. In addition, the data are missing of two important references; Schmid et al. (2004) on page 27 and Yoshizawa (1998) on page 28. 4. Disagreement with the past documents The correction factor N appearing in 1st paragraph on page 7 has been already deleted by ICRU and ICRP60. Hp(0.07) in 4th paragraph on page 17 seems to be nonsense for external monitoring of alpha-particles.