Purity Cults
Hi gb
Desires to be "pure", however defined, seem to be behind the visceral reaction people have to radioactivity regardless of how much they're actually, or likely to be, exposed to. Something similar drives the anti-GM campaigns of groups like "Greenpeace" - a clever triggering of people's disgust reflexes gets the right reaction everytime.
Purity, of race or thought, also drove the mass slayings conducted by the Nazis, the Chinese Cultural Revolution and the Kampuchean Communist Party. That "Greenpeace" want most of the human population dead is a down-played aspect of their rhetoric. And, of course, their leadership would probably decide who reproduces and who doesn't...