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Which radioactive isotopes can be found in nuclear fallout?
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atomic bomb
The first atomic bomb test, near Alamogordo, New Mexico, July 16, 1945.
Nuclear fallout from a fission device consists of a complex mixture of more than 300 different radioisotopes produced during the explosion. While many isotopes have short half-lives, those that remain radioactive for long periods pose the most significant health hazards.12
Prominent isotopes found in fallout include:
- Cesium-137: A long-lived isotope that is a significant component of fallout and can enter the food chain through plants and animals.23
- Strontium-90: Known for its long half-life (approximately 28 years), it is particularly hazardous because it is chemically similar to calcium and can accumulate in the bones of humans and animals.423
- Iodine-131: Although it has a relatively short half-life of eight days, it is easily detected in humans and animals because it selectively accumulates in the thyroid gland, where it can increase the risk of cancer.2
- Plutonium-239: Another long-lived isotope that can be present in fallout and is considered a significant hazard due to its accumulation in bone and bone marrow.42
In addition to these fission products, all materials in the vicinity of a nuclear blast may become radioactive, further contributing to the composition of fallout.41