I agree with you about cosmic radiation, but I was talking about solar radiation.
My optometrist today was specifically talking about the effects of UV.
I was not talking about scheduled pax flying at midnight, I specifically said 2am. That isn't "only shifting your nights sleep a few hours one way or t'other" (And if I'm working at that time I have almost never started work before 6pm, unlike the early- to mid- afternoon report times that those pax flights still on frequency at 2am have had.)
I don't experience "... hoovers slamming against [my] door in the bargain". I was concerned about sleeping during the day when I started this job, but I have found it to be hardly any problem. It has been immensely better than that dreaded alarm clock that used to go off at silly o' clock for 'earlies', that was a real 'killer' especially when having to set off for a 10 to 12 hour day at that silly o' clock.
But back to Job Security: I sleep comfortably at night not worrying about Job Security. This is a good sector of the industry to be in for Job Security.