Collective dose equivalent

The quantity 'collective dose equivalent' is defined and its applications discussed . Radiological protection policy for the exposure to ionizing radiations of individuals or populations requires an assessment of the resulting detriment, and the magnitude of this detriment depends in general on the number of people exposed, the level of exposure and the distribution of dose equivalent in the exposed group. For many practical situations, the quantity 'collective dose equivalent' measured in units of man rems is a useful measure of the total exposure of the exposed population. Its significance is discussed in terms of possible consequences for linear and non-threshold dose-effect relationships and also for two special cases of non-linear dose-effect relationships. The practical uses of collective dose equivalent, social policy for the inclusion of only those individual dose equivalents above some level corresponding to the trivial level of individual detriment and the establishment of limits on collective dose equivalents are all considered, and it is concluded that collective dose equivalent is a useful quantity in procedures involved in implementing an effective radiological protection policy for activities where numbers of people are involved. (U.K.)