kaesium137

Caesium-137 (137Cs) is a synthetic radioactive isotope of caesium. It is produced as a byproduct of nuclear fission, primarily in nuclear reactors and in the detonation of nuclear weapons. Caesium-137 has a half-life of approximately 30.17 years, meaning that after this period, half of the initial amount will have decayed. It decays by beta emission to a stable isotope of barium, Barium-137.

Due to its relatively long half-life and its chemical properties, which cause it to behave similarly to potassium and be readily absorbed by living organisms, caesium-137 is a significant environmental concern. It can be incorporated into the food chain, leading to internal exposure for humans and animals. Historically, major releases of caesium-137 into the environment have occurred as a result of nuclear accidents, most notably the Chernobyl disaster in 1986 and the Fukushima Daiichi nuclear disaster in 2011. These events dispersed caesium-137 over wide areas, contaminating soil, water, and agricultural products. Monitoring of caesium-137 levels in the environment and in food is an important aspect of radiation protection. It is also used in certain industrial applications and medical treatments, though these uses are less common than its significance as a radioactive contaminant.