Using a technique designed for dating fossils and archaeological artifacts, researchers have analyzed a fragment of a jawbone from a Hiroshima victim, uncovering radiation levels nearly double the fatal dose.
The study relied on technique known as electron spin resonance spectroscopy to retrospectively measure the radiation doses Hiroshima victims were exposed to 73 years ago.
Up until now, the researchers say, samples of human tissue from the site have never been analyzed for this purpose.
The measurements showed a dose of roughly 9.46 grays (Gy) in the Hiroshima jawbone – a high dose, according to the team.
‘About half that dose, or 5 Gy, is fatal if the entire body is exposed to it,’ says Oswaldo Baffa, Full Professor at the University of São Paulo's Ribeirão Preto School of Philosophy, Science & Letters (FFCLRP-USP), who supervised the study.