ATTACHMENT 1


Memorandum from Clyde E. Wilson, Chief of AEC's Insurance Branch, 
to Anthony C. Vallado, Deputy Declassification Officer, 
December 20, 1948.  Subject: "Review of Document by Knowlton". 
ACHRE No. DOE-113094-B, (1 p).


December 20, 1945


Anthony C. Vallado, Deputy Declassification
Officer, Declassification Branch
Clyde E. Wilson, Chief, Insurance Branch

REVIEW OF DOCUMENT BY KNOWLTON

REFER TO
SYMBOL:OPI:CEW

This document entitled "The Changes in the Blood of Humans 
Chronically Exposed to Low Level Gamma Radiation," by Knowlton, 
has been reviewed by this office and we concur in the opinion of 
Dr. Stoeckle that the fact that the studies were performed upon 
people does not subject the A.E.C. to undue criticism. In fact, we 
think the contrary would be true.

The results of the studies indicate that the tolerance levels for 
chronic exposure to gamma radiation which have been accepted both
within the A.E.C. and elsewhere may be too high.  We can see the 
possibility of a shattering effect on the morale of the employee 
if they became aware that there was substantial reason to question 
the standards of safety under which they are working.  In the hands 
of labor unions the results of this study would add substance to 
demands for extra-hazardous pay.  We can also see the definite 
possibility that general knowledge of the results of this study 
might increase the numbers of claims of occupational injury due to 
radiation and place a powerful weapon in the hands of a plaintiff's 
attorney.

We call to your attention the following quotation from our 
memorandum of October 15, 1948, in discussing the document "Health
Physics Instrumentation and Hazard Evaluation" by R. P. Evans.  On 
Page 33, paragraph 4, the International X-ray and Radiation 
Protection Commission is quoted as recommending that 'The evidence 
at present available appears to suggest that under satisfactory 
working conditions a person in normal health can tolerate exposure 
to X-rays or radiation gamma rays to an extent of about 0.2r/day of 
lr/week.' (Emphasis supplied).  It is apparent that the tolerance
levels were arrived at with definite qualifications.  With this bit 
of authoritative information a plaintiff's lawyer could make these 
standards appear to rest on very questionable foundations."  The
results of the present study tend to cast greater doubt upon the 
validity of the  tolerance levels since the persons being studied 
had average exposure of only .2r/week, about 2/5 the tolerance 
levels.

In view of the above considerations we think the question of making 
this document public should be given very careful study.

C.E.W.

Wilson:tm