Y
UNITED STATES
ATOMIC ENERGY COMMISSION
WASHINGTON 25, D.C.
Decenber 26, 1956
Dr. H. V. Weiss
Dr. 8. H Cohn
Dr. W. H. Shipman
Dr. J. K. Gong
.
ete
2Oan9
U. 3. Naval Radiological Defense Laboratory
Ban Francisco 24, California
Gentlemen:
I enjoyed your report, USNRDL-455 on the Marshall Island contamina-
tion from Castle. Your soil data need to be recalculated with the
available caleium rather than total calcium as the basis for the
Sunshine Units.
Could you analyse these soils for available calcium so the total
ecOlogical picture can be seen? These analyses
be done by
is
isotopic dilution using a neutral solution of Ca’’
and being
careful to use only the mininem amount of water so direct
solution by bacterial action may net cecur. Also use plenty
of soil, 2 or 3 pounds, if possible.
If you wish, send send the samples here to me and I shall run then.
I have done a number recently and the method works vel. (cf.
Gmith and Blume, Boi Sci. 77, 9 (1958)). A soil from Canton
Island has been analyzed but none from the Marshalls. ‘The
Canton soil gave about 100 grams of exchangeable calaium per
equare foot in the top 3 inches. This is as you see only a
small part of the total caleium so the Sunshine Units in your
Table 3.2 should be miltiplied by large factors. This wild
bring them into agreement with the levels found in the
herbage.
Very sincerely yours,
W. FP. Libby
CC:
Dr. Ponpkins
Dr. Dunning
ir. Eisenbud
WMP