From Bruce Schneier’s blog.
As a public service, let me now inform you, gentle readers, of some statistics.
Between 1988 and 1997, a ten year period, 427 people were killed by explosive devices, a rate of 42.7 per year. By comparison, 5,702 people died due to fatal occupational injuries in 2005. The American Cancer Society estimates 564,830 deaths in the US from cancer in 2006. Stroke killed 150,147 people in 2004. Coronary heart disease gave another 452,300 victims to the reaper in 2004. Ah, you say, but I’m in pretty good health, I work out and eat healthy (which makes you a rare citizen of this country), and I’m totally paranoid, so I’ll just park it at home and I’ll be safe, right?
3,030 people killed in home fires in the U.S. in 2005 (not counting the firefighters actually trying to put the things out). 3,306 unintended, non-boating related drownings in 2003. 13,700 people over the age of 65 died in 2003 from injuries sustained in a fall. 23,157 accidental poisoning deaths in 2003. All in all, 2,487,415(.9) people in the US are projected to shuffle off their mortal coil in 2007… which means (assuming that the 42.7 number is a reasonably accurate guess for 2007) that explosive-related deaths represent .00017% of the overall fatalities in the US every year.
Or, yet another way of looking at it, the population of the US is 301,139,947 (according to the aforelinked CIA factbook) which means one out of every 7,052,458 people will die from an explosive device, so the probability that you’ll be hoisted by someone’s petard is approximately .00000001418.
Now, this isn’t strictly speaking a rigorous analysis, because I’m grabbing statistics that are easily accessbile with a web search instead of doing a proper year-by-year correlation study, but any way you want to look at it, the likelihood of you being killed by an explosive device is so fantastically small in comparison to the thousands of other ways in which you can have your ticket punched that worrying about it is… well, actually, probably doing nothing more than increasing your likelihood of being one of the 65 million people in this country who suffer from high blood pressure (which leads to those stroke and heart disease fatalities as well as kidney failure and other things that also will make you dead as a doornail).
So, if you see an abandoned backpack, don’t lose your mind and call the bomb squad. Just check it for identifying information and turn it into the lost and found.