Environmental impact of nuclear power materials decay, they release particles that can damage the body and lead to cancer, particularly cesium-137 and iodine-131. In the Chernobyl disaster, releases of cesium-137 contaminated land. Some communities, including the entire city of Pripyat, were abandoned permanently. One news source reported that thousands of people who drank milk contaminated with radioactive iodine developed thyroid cancer. The exclusion zone (approx. 30 km radius around Chernobyl) may have significantly elevated levels of radiation, which is now predominantly due to the decay of cesium-137, for around 10 half-lives of that isotope, which is approximately for 300 years. Due to the bioaccumulation of
Isotopes of caesium only long after the nuclear explosion is over. The combined yield of Cs and Cs is given as 6.7896%. The proportion between the two will change with continued neutron irradiation. Cs also captures neutrons with a cross section of 140 barns, becoming long-lived radioactive Cs. Caesium-134 undergoes beta decay (β), producing Ba 134 directly and emitting on average 2.23 gamma ray photons (mean energy 0.698 MeV). Caesium-135 is a mildly radioactive isotope of caesium with a half-life of 2.3 million years, decaying, via emission of a low-energy beta particle, into the stable isotope barium-135. Caesium-135 is one of the 7