Attachment 16
                                 
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OFFICE MEMORANDUM                        UNITED STATES GOVERNMENT


TO:       Clyde Wilson, Insurance Branch       DATE:  December 8, 1948

FROM:     Anthony C. Vallado, Deputy Declassification Officer,
          Declassification Branch

SUBJECT:  REVIEW OF DOCUMENT BY KNOWLTON

REFER TO
SYMBOL:  ILLEGIBLE:ACV

At the suggestion of the Medical Advisor, I have attached for your
review and comment a copy of LADC 587 entitled "The Changes in the
Blood of Humans Chronically Exposed to Low Level Gamma Radiation,"
by Knowlton.  This document has been issued as an unclassified
report by Los Alamos, since it clearly falls within the open fields
of research.

We concur with Los Alamos that it is properly issued as
unclassified; however, prior to officially approving its release,
we would like to know whether or not your office would have any
objections to its declassification.  Please return the attached
copy to us, together with your comments at your earliest
convenience.

For your information I have attached a copy of the Medical
Advisor's comments regarding the declassification of the document
in question.

                         Anthony C. Vallado

Attachments:
1.   LADC 587
2.   Cy of memo fr Stoeckle to Vallado, 12/7/48

Vallado/fih

Anthony C. Vallado, Deputy Declassification     December 20, 1948
Officer, Declassification Branch
Clyde E. Wilson, Chief, Insurance Branch

REVIEW OF DOCUMENT BY KNOWLTON

REFER TO
SYMBOL:  OPI:ILLEGIBLE

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 employees
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 number 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 18, 1948, in discussing the document "Health
Physics Instrumentation and Hazard Evaluation" by R.D. 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
1r/week.'  (Emphasis supplied).  It is apparent that the tolerance
levels wore arrived at with definite qualifications.  With this bit
of authoritative information a plaintiff's lawyer could make these
standards appear to rest an 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:ILLEGIBLE