I’m a sucker for simple handwaving arguments, since those are the only ones I can remember in full detail.\u00a0 Please forgive my self-indulgence below, and don’t misinterpret my oversimplification as an underestimation of your<\/i> intelligence!<\/p>\n
IMNERHO, any discussion of relative hazards should begin with “normalization<\/b>“:\u00a0 the probability of a given person’s dying<\/i> is (so far) exactly 1.0; put differently, the probability that all of us will still be alive 200 years from now is (so far) exactly 0.0 — barring exponential growth of life expectancy and\/or “uploading” into hardware, we are all doomed.\u00a0 The only things we have any realistic hope of influencing are (1) how soon<\/i>, and (2) of what<\/i> we will die.\u00a0 Plus, of course, (3) what we will do in the time we have left.<\/p>\n
That being established, we can look to epidemiology for the current status of (2): according to the Canadian Cancer Society, cancer will kill 26% of men and 22% of women in Canada; your mileage may vary.\u00a0 Since cancer is what we worry about most from radiation exposure, I will neglect other modes of expiration.<\/p>\n
Are all<\/i><\/b> those cancer deaths due to radiation<\/i>?\u00a0 Since we cannot escape environmental radiation such as cosmic rays, that argument could be made.\u00a0 How would we test that hypothesis?\u00a0 Obviously, by comparing the incidence of cancer in populations with increased or decreased radiation exposure.\u00a0 But this requires an additional hypothesis about how<\/i> said incidence depends on exposure.\u00a0 How do we choose that<\/i> hypothesis?\u00a0 We must let the data guide us.\u00a0 We have<\/i> such data, ranging from the exposed survivors of Hiroshima and Nagasaki to the denizens of Ramsar to patients receiving medical irradiation to airline pilots and so on.\u00a0 This data suggests that there is<\/i><\/b> in fact a threshold<\/b> dose (let’s restrict it to whole-body all-at-once exposures, for convenience) below which there is no statistically significant increase<\/i> in cancer.\u00a0 There might even be a decrease<\/i>, but let’s leave that for later.<\/p>\n
To proceed further we need a much deeper understanding of mitosis, apoptosis and healing of DNA double-strand breaks.\u00a0 Much of this is well understood (I gather) by various medical researchers, but is well beyond my feeble grasp.\u00a0 So far no one has (to my knowledge) translated those understandings into what we need to make quantitative comparisons, namely a differential equation describing the time evolution of the probability of cancer developing under various radiation exposure schedules.\u00a0 We therefore argue about various empirical toy models based on bulk statistics — an unsatisfactory situation, to be sure!<\/p>\n
But there are still meaningful quantitative questions we can ask!\u00a0 For instance, what if a radiation release from some reactor accident raises the probability of dying of cancer from 0.260 to 0.261 for a million men?\u00a0 How many “extra” deaths does that mean?\u00a0 Zero<\/b><\/i>!\u00a0 Every one of those men was already doomed to die!\u00a0 “Oh come on, you know what I mean: how many extra premature<\/i><\/b> deaths?”\u00a0 [My reaction to that word is recorded at https:\/\/jick.ca\/?p=383<\/a> ] — but most people would answer, “1000 men!”\u00a0 That’s a lot!\u00a0 Wait… when<\/i> would they die?\u00a0 If the answer is 10-30 years later on average, perhaps the meaningful calculation would be of how many years of life would be lost<\/i>.\u00a0 This obviously gets complicated, but note how our qualitative<\/b><\/i> response depends on quantitative<\/b><\/i> numbers!<\/p>\n A completely different<\/i> question one could ask about the same scenario is, “Should any of those men be alarmed<\/i><\/b> at the increase of their probability of dying of cancer from 0.260 to 0.261?”\u00a0 Duh<\/i>.\u00a0 No<\/b><\/i>!\u00a0 And yet they all would be<\/i> alarmed.\u00a0 Because that’s how stupid human beings are.\u00a0 And this is why the same person in Canada who enjoys skydiving as a hobby is terrified of tritiated water from Fukushima.<\/p>\n","protected":false},"excerpt":{"rendered":" I’m a sucker for simple handwaving arguments, since those are the only ones I can remember in full detail.\u00a0 Please forgive my self-indulgence below, and don’t misinterpret my oversimplification as an underestimation of your intelligence! IMNERHO, any discussion of relative hazards should begin with “normalization“:\u00a0 the probability of a givenRead More…<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[],"class_list":["post-756","post","type-post","status-publish","format-standard","hentry","category-rants"],"gutentor_comment":0,"_links":{"self":[{"href":"https:\/\/jick.ca\/index.php?rest_route=\/wp\/v2\/posts\/756","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/jick.ca\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/jick.ca\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/jick.ca\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/jick.ca\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=756"}],"version-history":[{"count":1,"href":"https:\/\/jick.ca\/index.php?rest_route=\/wp\/v2\/posts\/756\/revisions"}],"predecessor-version":[{"id":757,"href":"https:\/\/jick.ca\/index.php?rest_route=\/wp\/v2\/posts\/756\/revisions\/757"}],"wp:attachment":[{"href":"https:\/\/jick.ca\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=756"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/jick.ca\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=756"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/jick.ca\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=756"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}