Presentazione

8.8.09 da "search.japantimes.co.jp"

NAGASAKI (Kyodo). A team of researchers has succeeded in photographing radioactive rays coming from the cells of people who died in the 1945 atomic bombing of Nagasaki.

The pictures are evidence that the nuclear "death ash" continues to emit radiation from a corpse even after 60-plus years, according to Kazuko Shichijo, an assistant professor at Nagasaki University, a member of the team.

Little progress has been made in the study on the effects of internal exposure to radiation. The team's success is the first of its kind in proving that atomic bomb victims were exposed to radiation from the inside as well as from outside.

"We have succeeded, from pathological perspectives, in proving that people were exposed to radiation internally," Shichijo said.

"It may help pave the way for unraveling its effect on health," she said.

The team studied anatomical samples of seven people in their 20s to 70s who had died by the end of 1945 from acute conditions after being exposed to the bomb between 0.5 km and 1 km from the hypocenter.

The team succeeded in photographing alpha particles, emitted when radioactive material decays, appearing in the picture as dark lines radiating from near the nuclei of the cells in bones, kidneys and lungs of the victims.

The team concluded the alpha particles were almost identical in length to those emitted from the plutonium used in the bomb dropped on Nagasaki.

"Plutonium passes through the human body when people are exposed to it from the outside," said Nanao Kamada, professor emeritus of radiation biology at Hiroshima University. "But the study shows that it enters cells and emits radiation from inside the human body.

"The effects of internal exposure to radiation have not been taken seriously in Hiroshima and Nagasaki," he said. "The study is important as it visibly captured the effects."