I got 20 mCi in all, a second dose while exercising.
Without trying to be too picky, what is a typical dose (in rems=rads)
received by an individual?
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REPOSTING AN EARLIER MESSAGE (PROBABLY LOST):
More trivia on the subject.
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20 mCi of Tc99m (or 0.010 Ci) refers to 7.4*10^8 decays per second.
This is due to about 2*10^13 atoms injected into Leigh. How many Tc99m
injections take place word-wide each day? Could somebody try to answer
this by Fermi method?
The Tc99m atoms which were in Leigh's body several days ago turned into
Tc99. They are no longer in his body (Tc is highly-soluble in water).
But practically all of them are still radioactive (T=2.1*10^5 years).
So the Fermi question can be formulated in a slightly different way.
How many atoms of Tc99 in one liter of sea water?
Units. Why do we have two names (Bk and Hz) for 1/s ? Because Bk refers
to a random process while Hz refers to a periodic process. Radioactive
decay would be linear, rather than exponential, if the average decay
rate were to remain constant. But how can the rate be kept constant
when the number of atoms (in the parent generation) becomes less and
less? By making the decay probability time-dependent. Older atoms would
have to have a much higher probability of decaying next year than those
which were manufactured (in a nuclear reaction) more recently.
Humanizing atoms? Sending older atoms to hospitals and injecting them
with gluons which have colored tags? Nature does not operate in that
way. Atoms have no memory of their age; the exponentiality of all pure
decays is the proof. I often tell this to students when they measure T.
Perfect predictibility would make anther extreme. No hospitals would
be needed in the world in which the day of each death was exactly
predetermined.
Ludwik Kowalski