1. 10 r/day - Irregularly distributed over an eight hour day, probably would not render a wit ineffective if received daily for 30 days or more. 2. 25 r/week - Received within one day per week, probably would have no effect on combat ability for 8 weeks or more. 3. 50 r/day - Received for a week probably would not affect the efficiency of a fighting unit at once, but some individuals would be incapacitated by nausea and vomiting. 4, 100 r/day ~ Probably would be acceptable for not more than 1 or 2 days, after which incapacitation is to be expected. 5. 200 r/12 brs - Can be regarded as equivalent to an instantaneous dose of 200 r. The first item, 10 r/day for 30 days, represents a total of 300 r and an irreparable dose equivalent to about 60 r. Continuation beyond 30 days will be contingent upon assessment of damage ascribed to the total irreparable dose. The 25 r/week schedule for 8 weeks represents a total of 200 r and an irreparable dose of 4O r. ‘the vagueness of the quantities cited is indicative of the real lack of date for setting standards. In theory, it is possible to assume an infinite number of conbinations of time-dose relationships. Accurate medical descriptions for all these conditions, however, are not possible. For an exposed population in a large fall-out area involving thousands of miles, the bulk of the exposures are likely to be supralethal or sublethal, and only a relatively small part of-the area affected will be in the uncertainty range regarding lethal and injury effects. On the basis of large animal studies conducted by Trum and 81