Radioactivity and Agatha Christie

I love re-reading Agatha Christie novels. Better still, I've purchased many of them as audiobooks for my iPod and I listen to them over and over again while I'm doing needlepoint, housework, working out in the garden, or walking. The other day I was listening again to The Pale Horse when a particular phrase struck me. Towards the end of the story our hero, Mark Easterbrook, is summing up the evidence while sitting with Inspector Lajeune when he rattles off the line, "Because we live in fear of fallout and strontium 90 and all the rest of it, we are amendable to the suggestion along the line of scientific talk." (p. 247 in the St. Martin' Paperback edition) That made me sit up because this summer I spent some time studying up on radioactivity in anticipation of a new unit I was designing to teach this fall on nuclear chemistry.

Solution of Strontium Salt
burnt in a Bunsen Burner
Flame

All this talk of strontium-90 must have been very much on the minds of everyone during the 1950s and early 60s with the advent of the atomic bomb at the end of the Second World War, and the arms race that became the Cold War. Strontium-88 is the stable isotope and I even use a salt of strontium for a flame test when teaching chemistry. It is a component of fireworks resulting in a beautiful red color.  But strontium-90 the radioactive isotope is a by-product of Uranium-238 fission. The problem with this isotope is that the human body treats it like calcium and sequesters it in bones and teeth. In the late 50s and early 60s researchers here in the US were collecting baby teeth and testing them for the presence of strontium-90.Turns out that children born in the 60s had a higher concentration of strontium-90 in their teeth as a result of exposure from the atmospheric nuclear tests that were being conducted at that time. Eventually many countries would ban above ground testing. (Radiation: What it is, What you need to know, by Robert Peter Gale M.D. and Eric Lax, Alfred A. Knopf, c. 2013)

Of course Christie would use current events in her novels. Those details help to make her stories believable and relevant. Perhaps today's readers are very unfamiliar with the subject matter as we no longer have to fear testing as much except for those rogue nations who are trying to catch up to other nuclear states. The Cold War may be over but the threat of nuclear weaponry isn't.