The Mighty Micromort
Posted by Martin Poulter on 19 June 2009
A new word in my vocabulary this week is “micromort”, meaning a one-in-a-million risk of death. On a typical day you are exposed to one micromort of risk. However, if you go hang gliding, that’s eight micromorts. Scuba diving is five micromorts. Taking an Ecstasy tablet gives you one micromort. You get one micromort from 230 miles travel in a car, 6,000 miles in a train or just six miles on a motorbike. It takes just one and a half cigarettes to give you a micromort. A horse riding trip gives you about half a micromort.
Statistician David Spiegelhalter (who spoke in Bristol this week) has suggested we use this measure as a standard scale for various kinds of deadly risk. For example, taking Ecstasy, smoking a cigarette, a long horse ride and a short motorbike journey all have roughly the same amount of risk, yet the conventional understanding of the danger of those things isn’t equal at all.