🔬general biology i review

Fallout

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Fallout is the deposition of radioactive particles from the atmosphere to the Earth's surface. It can significantly impact ecosystems and biogeochemical cycles by introducing harmful substances into soil, water, and living organisms.

5 Must Know Facts For Your Next Test

  1. Fallout primarily occurs after nuclear explosions or accidents, releasing radioactive isotopes into the environment.
  2. Radioactive fallout can disrupt nutrient cycles by contaminating soil and water, affecting plant and animal life.
  3. Cesium-137 and Strontium-90 are common isotopes found in fallout that can be absorbed by living organisms, leading to biomagnification.
  4. The half-life of a radioactive isotope determines how long it remains active in the environment; for example, Cesium-137 has a half-life of about 30 years.
  5. Ecosystems exposed to fallout may experience altered species composition and reduced biodiversity due to radiation exposure.

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