Fallout

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.

Review Questions

• What are two common isotopes found in radioactive fallout?
• How does fallout affect biogeochemical cycles in an ecosystem?
• What factors determine how long radioactive particles from fallout remain active in the environment?

Related terms

Bioaccumulation: The process by which substances such as pesticides or heavy metals build up in an organism over time.

Biomagnification: The increasing concentration of toxic substances within each successive link in the food chain.

Half-life: The time required for half of a radioactive substance to decay and lose its radioactivity.