Strontium-90

Strontium-90 (90Sr) is a radioactive isotope of strontium, a chemical element with the symbol Sr and atomic number 38. It is produced by nuclear fission and is one of the more hazardous constituents of nuclear fallout. Strontium-90 has a half-life of approximately 28.8 years, decaying into yttrium-90 through beta decay, which in turn decays into stable zirconium-90.

Production

Strontium-90 is produced during nuclear fission, which occurs in nuclear reactors and during the detonation of nuclear weapons. It is one of the numerous fission products that result when uranium-235 or plutonium-239 absorbs a neutron and splits into lighter elements. Due to its relatively long half-life and its similarity to calcium, strontium-90 is of particular environmental and health concern.

Chemical Properties

As a member of the alkaline earth metals, strontium shares many chemical properties with calcium. This similarity allows strontium, including the radioactive isotope strontium-90, to be incorporated into bones and teeth, where it can remain for many years, emitting beta radiation.

Health Effects

The primary health risk associated with exposure to strontium-90 is an increased likelihood of bone cancer and leukemia. This risk is due to its incorporation into bone and bone marrow, where its radiation can damage the DNA of bone marrow cells. Additionally, strontium-90 can affect the creation of blood cells, potentially leading to anemia and other blood disorders.

Environmental Impact

Strontium-90 can enter the environment through nuclear accidents, nuclear weapon tests, and the disposal of nuclear waste. Once in the environment, it can contaminate soil and water. Plants and animals can absorb strontium-90 from their surroundings, leading to bioaccumulation and potentially affecting entire ecosystems.

Detection and Measurement

The presence of strontium-90 in the environment and biological samples can be detected and measured using various techniques, such as liquid scintillation counting and gamma spectrometry. These methods allow for the monitoring of strontium-90 levels in the environment and the assessment of potential exposure risks to humans and wildlife.

Mitigation and Cleanup

Efforts to mitigate the environmental and health impacts of strontium-90 include the cleanup of contaminated sites, the safe disposal of nuclear waste, and the implementation of stricter regulations on nuclear tests and reactors. Additionally, treatments such as chelation therapy may be used to remove strontium-90 from the body, although this process can be challenging due to its chemical similarity to calcium.

Conclusion

Strontium-90 is a byproduct of nuclear fission with significant health and environmental impacts due to its long half-life and its ability to mimic calcium in biological systems. Monitoring, mitigation, and cleanup efforts are essential to manage the risks associated with this radioactive isotope.