Destructive Effects – AtomicBombMuseum.org
. “Black rain”
The Hiroshima and Nagasaki explosions yielded some 200 different kinds of radioactive isotopes, that is, nuclear fission particles of uranium and plutonium that escaped fission. Following the explosions, these and other materials irradiated by neutrons from the bomb, were carried high into the atmosphere.
The mixing of enormous amounts of airborne irradiated materials combined with heat and thermal currents from the firestorms led to rainfall in both cities within 30-40 minutes of the bombings. As the fallout particles were mixed with carbon residue from citywide fires, the result was the awesome—and injurious—“black rain.”
*Atmospheric dispersion begins in Hiroshima. (HIMAT)
This “black rain” reached ground level as sticky, dark, dangerously radioactive water. It not only stained skin, clothing, and buildings, but also was ingested by breathing and by consumption of contaminated food or water, causing radiation poisoning.