The first three of these effects are “prompt” effects, because the harm is inflicted immediately after the detonation. The debris is carried by the wind and falls back to Earth over a period of minutes to hours. When a nuclear detonation occurs close to the ground surface, soil mixes with the highly radioactive fission products from the weapon.
Relative to other effects, initial radiation is an important cause of casualties only for low-yield explosions (less than 10 kilotons).įallout. Nuclear detonations release large amounts of neutron and gamma radiation. Though difficult to predict accurately, it is expected that thermal effects from a nuclear explosion would be the cause of significant casualties. In some cases, the fires ignited by the explosion can coalesce into a firestorm, preventing the escape of survivors.
Unlike conventional explosions, a single nuclear explosion can generate an intense pulse of thermal radiation that can start fires and burn skin over large areas. The shock wave can directly injure humans by rupturing eardrums or lungs or by hurling people at high speed, but most casualties occur because of collapsing structures and flying debris. Nuclear explosions produce air-blast effects similar to those produced by conventional explosives.
The health effects of nuclear explosions are due primarily to air blast, thermal radiation, initial nuclear radiation, and residual nuclear radiation or fallout.īlast.