I don't think "read Conan the Barbarian" is the main takeaway of that, though I'm sure "rays" was a trope in fiction.

Quack "radioactive medicines" actually happened to people. Product darwinism and actual customer darwinism.

See, e.g. https://en.wikipedia.org/wiki/Radioactive_quackery

https://www.orau.org/health-physics-museum/collection/radioa...

https://histmed.collegeofphysicians.org/for-students/radium/

https://www.dannydutch.com/post/the-strange-story-of-eben-by...

https://www.washingtonpost.com/health/the-lethal-legacy-of-e...