“The dosage is the poison”. Gamma radiation is what we call a particular form of energy transfer – that from very short wavelength electromagnetic waves (photons). When they are initiated from radioactive decay processes there is no difference in the energy from one atom or another.
The danger lies first in the initial exposure and only later in exposure time. That is, a shorter half-life compound will emit more gamma rays in any period of time than one with a longer half-life. We don’t like the idea of “long” half-lives meaning that the stuff will be around a long time, but the fact is that shorter half-lives usually mean more dangerous radiation levels.
As noted in your reference, the N-16 with a very short half-life posed a greater health risk requiring temporary special protective measures. But fundamentally the exposure to gamma radiation (or other) is a function of the amount of the starting material.
Best regards,
Steven
