Radiation safety

Radioactive substances leave electron ‘fingerprints’ behind

Walls can’t talk, but scientists can now read stories written in their subatomic particles. And that could make it harder to store radioactive material in secret.

Nuclear radiation rearranges the electrons in insulators such as brick, glass and porcelain. So comparing the positions of electrons in atoms at different spots on walls, windows and floors could provide a rough snapshot of where radioactive material was once stored and how strong it was, researchers report online July 3 in Health Physics.

This technique could also help identify the source of radioactivity — which is important for judging whether a room contained legal radioactive material with a scientific or medical purpose or if it housed a substance used for making nuclear weapons.