5-2-5-1Initial Radiation and Residual Radiation

Of the intial radiation emitted by the atomic bomb, it was the gamma and neutron rays that reached the ground and significantly affected the human body.

Residual radiation includes "induced radiation," which occurs when soil or building materials have been made radioactive by exposure to neutron radiation, and nuclear fallout, which falls to the ground such as raindrops containing radioactive soot and dust that were propelled into the atmosphere. In addition to external exposure, residual radiation may harm the body through internal exposure, the absorption of radioactive material that enters the body with food or air.