-28-
Pre-Nectar samples of clam kidney collected April 15,
19548
when recounted in 1957. contained almost (70%) as much radio-
activity as the post-Nectar samples, indicat‘ng that mich more
radioactivity vas contributed by the Mike test, Nowerler 1, 1952,
than by later detonations, chiefly Nectar.
Microscopic examination of kidney smears of Tridacna shows
a profusion of highly refractive granular inclusions which are
assumed to be responsible for some unusual properties of this
tissue, in addition to its dark brown color. The specific
gravity and ash content of kidney are high, the level of radioactivity is high, and the decline and decay rates are slow.
Lowman, et al. (1957:2£) showed by resin column analysis on
December 18-24, 1956 of a sample (plates 1282 and 1284) of clam
kidney collected at Belle on September 22, 1956, the following
radiotsotopic composition:
Pe55 -------- 74S
C060 --------- 1.8%
Coo8 -------- 9.2%
ZrI5-NbID ---- .15%
Co5T -------- 9.6%
y91
--.----- 2.6%
Mn54 -------- 2.2%
Rul6_pyl% -- .7Hg
Fe? --------- ~15%
The preponderance of Pe) is missed in end-window beta or in
amma counti
70 KV X-rays).
because of the low energy of its emission
At the same time gamma spectrometry of the
sample above as well as two other analyses of kidney samples
collected at Be lje in June-July, 33°" and March-November,
showed only Rul06-Rnl26, mn54, CoOX, and Co57.
1955
It 1s probable
that Fe55 would have been detected by resin column analysis of
the 1954-55 matertal.
X-ray spectrometric analysis on December 19, 1957 of the
ash of kidney from a 12-inch tridacnid clam (Hippopus), collected May 12, 1956 at Leroy Island, showed the most abundant
non-radioactive heavy elements to be bromine, strontium, and
zine, with a small amount of tron.