I read studies and, though most were garbage, I cobbled together some idea of what I was in for. The biggest one: relative risks of tongue, mouth, and esophageal cancer in the 2-5 range compared to non-smokers. That’s for a bowl per day, and I average a quarter of that.
I found that if I drank my beloved whisky with a pipe, and smoked a pipe several times per day, the relative risks of these cancers went up to 18 or more. That is more than I was comfortable with, so I don’t do that.
I also did the same with motorcycle riding. In California studies, one was 47 times more likely to get in a fatal accident than a car driver. I looked at what caused that increase in the studies and mitigated them: don’t drink, don’t commute, don’t ride tired, wear a high vis helmet, etc. The stats give me 3-4 times the likelihood of an accident per kilometre. That’s good enough for me.
I will note that the gentleman who started the thread goes into small boats in the frozen North Pacific. He flies a single engine plane over unforgiving wilderness. And he likely has bears wander through his hunting camp while he slumbers a few feet away, a half millimetre of rip-stop nylon between himself and posterity. Were there studies on the relative risks of each of these activities, I would bet they would put the risk of a bowl or two a week to shame.
In answer: Like every car driver, I mitigate my risk to levels I am willing to take, but don’t eliminate it.