teken, Thus, by necessity, the mst practical eriteria upon which to base a decision are gama dose rate readings, which are in turn related to the aaount of fallont. Dose The most immediate solution might be to establish lower permitted dose rate levels at later times after dctonation. However, if a series of Gose rates are established for increasing tines after detonstion so that their relattonship follows t™)°?, then the doses delivered in X hours (before the material is washed off) will be greater for earlier tines after detonation, If one vere sure of the tine that the fallout eaterial vas to renain in place, then a scale of dose rates versus tine after detenstion could be made to yield the same total dose over the X hours. Since there is obviously no set tine period for duration of contact that would be valid for all eases, one might assuze the wrst case where the saterial remains inplace until its activity has decayed to an insignificant level, Dose rates could then be approximated, to yield a given infinity dose, by: Be 5it wheres D ® infinity dose 4 @ dose rate at tine "**, If the above discussion is accepted, then the rezaining question is to set the infinity dose. Here, we mist be clear that whereas the meazurenents taken by the monitors, and the data upon which action will be desided will be gamma dose rate readings, the point of principal concern is the beta dose delivered to the basal layer of the epidermis (assumed as 7 milligrams per square centineter). The ratio of exission of beta to gamma fs a function of