We've always had radiation, the calm, Jack Webb sounding narrator assures us. It's just too much of it at once, like anything else. Too much water can kill you, and too much food, so just avoid too much radiation in the form of fallout after the A-Bomb goes off, and you'll be fine.
This was the government line for decades, and it always struck me that survival is fine, if that's all you want out of the world. Maybe I was brought up to be selfish and greedy, but is survival enough? Was survival enough?
Of course not, and that was what we would have been confronted with if someone had dropped the Bomb. But in case they didn't, like Douglas Adams would, the government would urge you "Don't panic!"