eorenee
Fe5S is me dominant radioisotope in tiseues of fish from Eniwetok aad
Bikini Atolls. Mn54 is often present in fish tissues but only in small
amounts.
Some differences in radioisotopic content of certain organs in the
same fish have become evident.
Bone, for example, differs from most
other tissues in lacking Co9?, Co58, and Co®®, although considerable
amounts may be present in the muscle and liver of the samefish.
If the radioisotopes in Table 7 are used and the half lives weighted
by either the per cent of total activity or the d/m/g wet weight,
the
estimated generalized decay of the radioactivity in the sample indicates
an approximate 380-day half life for the period between the summer of
1957 and the summer of 1958.
An estimation of the biological half life of the radiosotopes in the
fish of the Rongelap area would be even more speculative.
However, if
the comparisons of the decline and decay in Figures 1 and 2 are indicative, it would appear that the biological half life {s
longer than that
estimated for physical decay in the previous paragraph.
It would be of
value to know the biological half life of each of the radioisotopes in
the Rongelap environment.