°
ie
internal methane gas-flow counting chambers at the Laboratory of
Radiation Biology in Seattle.
Counts per plate were converted to disinte-
grations per minute per gramof wet tissue by correcting for sample
weight,
geometry, backscatter and self-absorption.
For a more complete
discussion of these procedures see Donaldson et al. (1953).
Other tissues were treated similarly, with the exception of liver,in
which case the whole organ was removed from each specimen.
If a suf-
ficient number of specimens of a single species was obtained, the tissues
were treated separately as in the case of goatfish and halfbeak from
Kabelle Island (see Table 1).
5
Rey
Decay rates for radioactivity of tissues of fish collected in 1956 were
calculated because there were indications that Rongelap Atoll was
contami-
nated during the Redwing operation.
Gamma spectra and total gamma counts were made on dried or ashed
samples in a single channel,
50-position,
automatic advance, gamma spec-
trometer using a two-inch, well-type sodium iodide crystal.
Chemical
analyses were made by ion-exchange resin column and radiochemical
cipitation techniques
pre-
The radioactive isotopes contained in the separate
fractions were identified by determination of the gamma energies,
beta mass absorption studies using aluminum foil.
and by
Correction factors for
converting beta and gamma counts to disintegrations per minute were calculated by the use of standards of known energies.
used are given by Lowman et al. (1957).
Details of the procedures
DOE ARCHIVES