Micromort

A micromort (from micro- and mortality) is a unit of risk defined as a one-in-a-million chance of death. Micromorts are usually assigned per event, or per unit of time a person is exposed to something. Micromorts can be used to measure the riskiness of various day-to-day activities. A microprobability is a one-in-a million chance of some event; thus, a micromort is the microprobability of mortality from an event, or the health impacts of an event. The micromort concept was introduced by Ronald A. Howard who pioneered the modern practice of decision analysis. Micromorts for future activities can only be rough assessments, as specific circumstances will always have an impact. However, past historical rates of events can be used to provide a rough estimate. A related and somewhat opposing unit is the microlife, which measures statistical improvements to life expectancy from an activity—one example being regular aerobic exercise.