# View Comment

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The changes proposed are welcome since the new approach is much simpler. However the following points may be considered: The value of effective dose given in ICRP-74 using the anthropomorphic phantom do not seem to be different from the value of effective dose given in ICRP-116 using the voxel phantom for photon energies between 200 keV to 1 MeV. However, the value of Hp(10) was chosen such that there would be an over-estimation of effective dose even in these energy ranges. Now, there is a sudden shift and it is required to measure effective dose without any over-estimation. Though the concept of personal dose is easier to understand and seems more appropriate, there should be more explanation for the reason for the shift, especially since it seems to mean a reduction in individual doses for a large majority. The fact that Hp(10) overestimated photon doses for < 70 keV was well-known. However, the fact that the RBE for lower energy photons is higher has also been highlighted and the overestimation of Hp(10) was justified with (ICRP-103): "In this case of external exposure, however, the operational dose quantities H*(10) and Hp(10) are used for radiation protection monitoring and for assessing effective dose. For photons with energies between 10 keV and 40 keV and frontal irradiation (AP) of the body, H*(10), is up to a factor 6 higher than E and, for other directions of radiation incidence (PA, LAT, ROT, ISO), this conservatism is even greater" . It is not clear how the use of wR of 1 can be justified for lower RBE in the present case. 2 sets of conversion coefficients for photons (from air kerma) are given, one with kerma- approximation and the 2nd set with (possibly) full transport calculations. As expected, these values are different for energies above 1 MeV and below 70 keV. Kerma approximation may be more suitable in practical situations which involve broad spectra and wide angular distributions and electron scattered from the air and surroundings (ICRU 43). This should be explained clearly. Table A.3.2 of Conversion coefficient from neutrons Fluence to Directional and Personal absorbed dose to lens of eye and the corresponding figures are not provided Table A.4.2.1 of Conversion coefficient from neutron Fluence to Directional and personal absorbed dose in local skin on the slab phantom and the corresponding figures are not provided Line No. 495, For operational quantity The ambient dose, H*, the conversion coefficient h*Emax,i(Ep) used for i
Line No. 582, For operational quantity, The personal dose, Hp, the conversion coefficient hp,i(Ep,Ω) = used for i |