I know how deadly it can be. The thing about the chemical stuff is that it smells bad, it look dirty etc. Once we wandered in an old building that had a huge pool like thing filled with something that smells like freshly roasted nuts. A pleasant smell but its out of place, therefore run away.

Playing with lead, you notice that it lives traces on your hands, it looks wrong so you try not to play with the lead anymore.

A lightbulb with a shiny liquid in it? Don't break it or break it in open air at safe distance. Even if you touch the liquid make sure you wipe it out clean as it looks unnatural.

You easily develop instincts to detect what's dangerous with machines and chemicals, with nuclear you can't do that.

Ans as for the active ones, I hope they are taking good care of them. Bhophal 2.0 is indeed possible.