> inadvertently built using steel laced with radioactive elements. > Statistical analysis on them showed lower affinity for cancer

Radiation Hormesis might be real (I hope so), but if it gets through drywall, it would be a different form of radioactivity to the one I grew up around.

Alpha decay needs just a simple sheet of paper (or dead skin cells) to stop the radiation, but it messes with DNA if you happen to eat it or breathe it.

That's the one from Th-232, in comparison bananas are also naturally radioactive, but the K-40 emits beta particles, which doesn't cause as much damage.

Alpha decay is what a cup of Polonium tea would have (from the infamous assassination).