Additionally, vulnerable people are disproportionately affected by secondhand smoke exposure due to having less control over their living and working conditions
(Doohan tried to keep the missing digit concealed during most of his postwar acting work.) Doohan survived those wounds, which did not damage any major organs or arteries
In fact, the medical and scientific literature makes this a prime example of historical revisionism, if not pure myth
Ronald Fisher, Cigarettes, Cancer, and Statistics, The Centennial Review of Arts & Science 2 (1958): 151-166
Alternatively, in preparation to quit, you can actually measure what cigarette smoking does to your sleep, stress levels, and heart rate variability