US testing of nuclear weapons has resulted in about 800,000 premature fatal cancers throughout the globe, and the nuclear tests of China, France, India, Russia, and the UK have added to this total. Surprisingly, however, these avoidable deaths have not received much attention, as compared, for example, to the smaller number of US fatalities on 9-11-01. This essay (1) surveys the methods and models used to assess effects of low-dose ionizing radiation from above-ground nuclear weapons tests and (2) explains some (...) of the epistemological and logical problems (with these methods and models) that have caused scientists to decide against health screening of the most likely test victims. It also (3) argues that, once the faulty presuppositions and question-begging frames about testing and screening are recognized, there are compelling arguments in favor of nuclear-test nations'' screening fallout victims, at least among their citizens. Finally, it (4) suggests that logically and epistemically flawed fallout studies/recommendations against screening are more like to occur when scientists adopt a Laudan-style comparativist rationality, rather than when they adopt a metascience more like that of Kuhn and others. (shrink)