-7fish as a food of man,
upon other radioactive organisms,
like land plants or animals, can be a pathway by which
radioisotopes are transferred from the environment to man.
The presentation will include a discussion of the nature
of radioactivity,
radiations,
the biological effects of ionizing
the evaluation of hazard from internal emitters,
the distribution of radioisotopes in the sea,
and the up-
take of radioisotopes by fish.
The Nature of Radioactivity
The biological effects to be expected from exposure
to radioactivity can be explained,
in part,
by the nature
of the energies that are released from the nucleus of an
atom of a radioisotope.
a nucleus,
All atoms consist principally of
in which there are protons and neutrons,
electrons that orbit about the nucleus.
and of
Each chemical
element is characterized by having a specific number of
protons in the nucleus;
however,
the number of neutrons
associated with any given number of protons may vary.
Atoms
with the same number of protons but with various numbers of
neutrons are known as isotopes of the element.
For example,
in the nucleus of the iron atom there are 26 protons, but