Risk to groundlings of death due to airplane accidents: a risk communication tool.

During the period 1975-85 in the United States the 70 year lifetime risk of dying from being hit by an airplane when the individual is on the ground was 4.2 per million people. In contrast to many other risks used for comparison purposes, risk to those on the ground from an airplane crash is not a function of our own skills; is not optional; provides no benefit to anyone involved; and is not an act of nature. As a risk comparison tool it also has the useful characteristics of being something about which we can agree that regulatory action, such as control of airplane use and traffic, is warranted; but that no significant change in personal behavior, such as living in the basement to protect against dying from a plane hitting the home, is commensurate with the extent of risk.