A victim's jawbone has revealed the intensity of Hiroshima radiation after the U.S. dropped the first atomic bomb the Japanese city during World War II in 1945, and the result was stunning, according to The Washington Post.
The study of the jawbone collected 27 years after the bombing by Brazilian physicist Sérgio Mascarenhas, who was at the time a visiting professor at Harvard University, could not be completed in the 1970s because of technology, the newspaper said.
But a new technique called electron spin resonance has allowed new researchers to complete his work, revealing that the jawbone had absorbed 9.46 grays, a measurement of radiation absorption into the body, from the Hiroshima attack, the Post said.
The jawbone test revealed that the victim absorbed almost twice the amount of radiation that would have killed a person, about five grays, according to the newspaper. The technique and study was detailed in the journal PLOS One that was published in February.
"As an attempt to use biological materials collected from the victims themselves, in August 1972 one of the coauthors of this paper (Mascarenhas) visited Japan, contacted Japanese scientists working on nuclear medicine, and obtained human samples from the atomic bomb site," the study's introduction said.
The study said that, with the help of two Japanese scientists, Mascarenhas was given bone samples of survivors from the bombing site, including the jawbone the following year. Mascarenhas would tell the American Physical Society meeting in April 1973 that specific calculations could not be achieved with 1970s technology, the Post wrote.
Oswaldo Baffa, a professor at the University of São Paulo, and his former student Angela Kinoshita, now a professor at University of the Sacred Heart in Brazil, used electron spin resonance to finish the research, the Post said.
"There have been major improvements in the instrumentation to make it more sensitive in the last 40 years," Baffa told the Brazilian science news website Agencia FAPESP. "Now, you see digitally processed data in tables and graphs on the computer screen. Basic physics has also evolved to the extent that you can simulate and manipulate the signal from the sample using computational techniques."
Kinoshita told the Post that the research is just now giving scientists' clarification of the impact of the 1945 bombings.
"When one imagines all the processes involved in an episode such as this, there were many doubts about the possibility of using this methodology to determine the [radiation] dose deposited in these samples," Kinoshita told the Post.
"This work demonstrates this possibility and may open several possibilities for future work that may analyze details of this nuclear attack that can be clarified with the determination of these doses."
From 90,000 and 166,000 people died after the Hiroshima bombing while another 60,000 to 80,000 were killed in the atomic bomb dropped on Nagasaki, the Post wrote.