A comparison of the rete at which levels of activity in
orgaaisme of the same species change with the passage of time,
herein termed
» with the rete of physical decay, should
indloate changes
eavalilebllity of the radioactivity to the
opgenisa concerned.
If decline is more rapid than decay @ reduction of activity in the environment beyond that caused solely
by physical decay is suggested, and conversely, a steeper decay
than decline suggests either an increese in availability in the
environment or an sccuwsulation or concentration of radioactivity by the organism. Equality of decay and decline suggests
that upteke end excretion of rediolsotopes have reached an
equilibrium with the environment. It will be shown that cases
in which physical decay progressed more rapidly than did the
rete of decline over the same period of time vere rare or lecking.