The Penalty Table was developed to provide a simple guide when decisions must be made that will involve some risk. The choice of the numbers was based on judgment derived from extensive clinical radiotherapy experience, pathological studies of radiation-accident victims, and laboratory experience with numerous large and small animals. There is no directly applicable disaster or laboratory experience involving humans that clearly supports the choice of all of the numbers in the Penalty Table.
There is also no satisfactory biological model or mathematical formula relating radiation effects (of the type considered here) to exposure rates and durations that provides a satisfactory basis for deriving the amounts of exposure indicated in the table for time periods greater than one day. These are the best numbers available at the present time for this purpose.
Three examples of the Penalty Table are given here:
Example 1 – It would be best if everyone’s radiation exposure could be kept as low as possible, but due to wartime conditions, some individuals may have to spend some time in areas of higher radiation levels. Suppose you are trying to limit their radiation exposures to levels resulting in low risk. The numbers in Row A of the Penalty Table above apply in this case. According to these numbers, it would be necessary to limit the total radiation exposure of individuals to less than 150 R in any one week (column a), 200 % in any one month (column b), and 300 R in any four-month period (column c).
For example, if individuals were exposed to the one-week limit of 150 R (column a) within the first week, then the limit for additional exposure during the following three weeks of the first month, to keep within the one-month limit (column b) would be 200 R – 150 R = 50 R.
This additional exposure of 50 R could be received at any rate (for example, by going outside the bomb shelter into areas of higher radioactivity) during the following three weeks of the first month, without exceeding the one-week or one-month limits in the Penalty Table.
However, if this additional exposure of 50 R were received, for example, within the second week, then the individuals would have to be kept completely free of further exposure (which may not be possible) during the remainder of the first month to keep within the one-month limit for Row A (200 R). Similarly, if the individuals were exposed to the limit of 200 R in the first month, without exceeding 150 R in any one week of that month, the limit of additional exposure for the following three months of the first four months (colum c) would be 100 R, for a total of 300 R (200 R + 100 R) in four months.
Example 2 – Suppose you need to conduct operations at the intermediate level of radiation exposure, involving significant medical risk (Row B), justified by highly critical emergency situations. The decision to conduct such operations must involve the bomb shelter Manager.
In this case, the decision-maker may find it necessary to allow greater exposure than one or another of the limits indicated in Row A but would be constrained whenever possible by other limits in Row A and always by limits in Row B of the Penalty Table.
For example, if individuals who have been exposed to 150 R within the first week are required in some emergency to be exposed to an additional 200 R during the remainder of the first month (for a total of 350 R in the first month), it is desirable, if possible, that the one-week constraint for Row A (column a) be observed by allowing no more than 150 R of this additional exposure during any one week within that month, even though the one-month limit (200 R) and four-month limit (300 R) for Row A will have been exceeded and the one-month limit (350 R) for Row B will have been reached.
If it is not possible to keep within any of the constraints for Row A, then the Row B constraints have to be applied. In other words, you try to keep exposure in any one week as far as possible below 250 R and to limit the exposure during the first month to 350 R. Any additional exposure after this first month must be kept as far as possible below the additional 150 R which would attain the four-month limit of 500 R (Row B).
As in example 1, the decision-maker could schedule exposures in a variety of ways within the constraining limits to meet the work required by the problem at hand.
Example 3. Suppose you need to conduct operations at the high levels of medical risk (Row C), justified only by extremely critical emergency situations. Again the decision to conduct such operations must involve the bomb shelter Manager. Those activities that could result in saving a significant number of lives may call for the deliberate exposure of some persons at the highest constraint levels, where radiation sickness and a 50 percent probability of death are expected (Row C). If such situations arise, the decision-makers would use for guidance Row C of the table in a manner similar to that discussed for the low- and intermediate-risk rows (A and B) in examples 1 and 2.
After a time of no more than two weeks, it should be possible to move people from areas of high radiation levels to areas of lower radiation levels. In the areas of lower radiation levels, people should be able to get outside and work for different lengths of time as long as their radiation exposures stay within the limits of Row A of the Penalty Table.
The “one-month” and “four-month” columns of the Penalty Table are intended primarily for these situations. No one should have to stay totally confined inside the bomb shelters for more than two weeks, although people may have to live in them in some locations for longer periods.