-~2from the sea. Aquatic forms may be destroyed by atomic detonations
from external sources of ionizing radiation.
The radioactive
material that is absorbed or ingested with the food and retained
in the organism as an internal emitter is, however,
of much more
concern.
The effects of ionizing radiation upon aquatic forms are
most difficult to measure directly in field situations such as
those that prevail at or near the test sites.
Foster
(1957)
Donaldson and
have reviewed the literature from laboratory-type
experiments:
A broad review of the results obtained with the
organisms of different phyla indicates that the lower
or more primitive forms are generally more resistant
to ionizing radiation than are the more complex verte-
brate forms /*] Welander (unpublished data) has summa~
rized much of the data for which some approximation
of dose can be made.
Table 1 is a further conden-
sation of these data which were obtained in experiments
where whole body doses
tered.
(usually X-rays) were adminis-~
Owing to the great variety of circumstances
under which the experiments were conducted, these
data represent only orders of magnitude of effects.
The algae and protozoa are most resistant with
Leo values in the order of many thousands of
roentgens.
The molluscs and crustaceans are somewhat
more sensitive, with LD.5 values of a few thousand roentgens
i] see Figure l.