Is there a need for radiation quantities defined in the body of the individual?

The ICRU, in Publication 39, defined quantities in terms of dose equivalent in standard tissue within the body of the individual. It has been suggested that these quantities cannot be precisely measured, and are in any event unnecessary since the value of the quantity can be taken to be equal to the reading of an approved dosemeter, calibrated on a standard phantom. It is argued in this paper that the ICRU quantities are useful because they can be applied to any body site in addition to those on the trunk. The suggested alternative approach would, for example, give significant errors if applied to intermediate energy neutron dosimetry of the extremities. At a more fundamental level, quantities defined in the body of the individual are needed for legal rigour, since rogue readings can never be eliminated entirely. (author)