This Wikipedia article notes that each of us faces about 39 micromorts on any given day of our life, though this is based simply on an assumption of a seventy year (25,000+ days) lifespan. Such a measure includes natural death, of course, so the greater value is on measuring the increased risk of various activities.
The linked article lists the degree to which we would have to engage in certain activities to achieve one micromort of risk. For example, drinking half a liter of wine is said to carry with it one micromort of risk of death from cirrhosis of the liver (I've read that drinking wine in moderation has certain health benefits, so I wonder if those benefits might counter this increased risk). Smoking 1.4 cigarettes also has one micromort of risk, which would mean each pack is worth about 14.3 micromorts (with no known offset). So back when I was smoking two packs a day, I was racking up over ten thousand micromorts a year.
In terms of accidental death connected with various means of travel, we learn that the following equal one micromort:
- 6 miles by motorbike
- 17 miles by walking
- 10-20 miles by bicycle (sources differ)
- 230-250 miles by car (sources differ)
It's interesting that travel by car is far safer (in terms of distances) than walking or biking – though, as with wine, those activities have health benefits that I suspect more than offset their dangers.
Two activities that I have sometimes engaged in are also mentioned. Scuba diving has a risk factor of 4.7 micromorts per dive, while skydiving is worth seven micromorts per jump.
The next time one of my smoker friends gets on me about jumping from planes (which I have done, alas, only a few times, due to the cost), I need to remind them that five of the cigarettes they smoke equal one jump.