128 RADIATION STANDARDS, INCLUDING FALLOUT These assumptions are discussed in some detail in the background report, I might say. ; The report showsthat the average iodine 131 intakes during certain periods were in range III of the Federal Radiation Council guidance. Mr. Ramey. Could you outline what you mean by “range ITI” of the three ranges so we can get the picture of that. Dr. Cuapwicx. Yes, sir. To start as a kind of anchor pointin the range system, the upper limit of range II is a daily intake which if sustained constantly, or if values were to average at that level, would correspond to a dose equal to the radiation protection guide or the radiation dose that is considered acceptable for normal peacetime operations. , The other two ranges could be described as follows: The upperlimit of range I is a factor of 10 belowthis intake and the upper limit of range III is a factor of 10 above. The Council indicates that operations should be conducted in such a manner that the total daily intake of the average daily intake over the year does not exceed the upper value of range IT. It indicates that when intakes are in range ITI, an effort should be made to reduceintake to a lowerlevel. Mr. Ramey. That is for a whole year? Dr. Cnapwick. Thatis right. Chairman Horirretp. That is qualified by the fact that your sentence says that the average iodine 131 intakes during certain periods were in range III of the Federal Radiation Council guidance. You say certain periods. Was this a matter of a few days out of the year? Dr. Cuapwicx. I am going to develop this ina little bit more detail, sir; and perhaps I will cover in general your question. Representative Price, Will you proceed, please. Dr. Cuapwicx. The Council states: Transient rates of intake within range III could occur without the population group exceeding the RPG if the circumstances were such that the average annual intake fell within range II or lower. The report shows that this was the case for ail the stations as well as for the national average during the 5-month period, which was 60 pyc (micromicrocuries) per day. It is useful to consider estimates of the radiation dose to the thyroid from iodine 131 during this period and compare these estimates with the RPG. Using the above assumptions and the relationship between intake and thyroid dose provided by the Federal Radiation Council Report No. 2, doses were estimated for infants with a 2-gram thyroid, consuming milk from each of the samplingstations. RANIRRERGRSSSccaectaens soy 61 Logtet ShesPRATERCATBE UME is