This is not how radioactivity works. There’s lots of construction material that has isotopes with a long half life. But the long half life means it’s barely da

This is not how radioactivity works. There’s lots of construction material that has isotopes with a long half life. But the long half life means it’s barely dangerous (less dangerous than background levels of radiation in many habited places in the world). The stuff that’s actually dangerous for humans are isotopes with short half lives. Those isotopes, by definition, don’t last long.