I read the nutshell version. It sounds like the completely ignored that people who work graveyard are more likely to smoke, drink, eat garbage, drive lousy cars with factory installed exhaust leaks (that's ok, the driver's window is often missing), and engage in other risk taking activities.

You could make the argument that graveyard might be tied to suicide rates- I've worked it, and the only happy, perky people I ever dealt with were either begging for a freak industrial accident, had participated with brain transplant experiments with squirrels, and/or were on something. Everybody else was depressed.

Long and short version- if it doesn't give you cancer, it will give you high blood pressure or potentially dangerous colon blockage. I think people need to grow up and accept that they are mortal.