So the important thing to know is that longer lived isotopes are less dangerous than shorter dated isotopes. Inversely proportional actually [1].
[1] https://en.wikipedia.org/wiki/Technetium-99m
[1] https://en.wikipedia.org/wiki/Technetium-99m
Comments
The longer dated isotopes are so inactive they might as well be background radiation. In fact, for them to do damage they need to be ingested or inhaled.
From hostile architecture, to death symbols.