the estimated dose for an area or region multiplied by the estimated population in that area or region. For more information, see " Primer on Radiation Measurement" at the end of this document.

The sum of the individual doses to all members of a specific population.

The sum of the individual doses received by each member of a certain group or population. It is calculated by multi- plying the average dose per person by the number of persons within a specific geographic area. Consequently, the collective dose is expressed in person-reins. For example, a thousand people each exposed to one rem would have a collective dose of 1,000 person-rems.