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
Radiation effects from the Fukushima Daiichi nuclear disaster caesium in most samples. From the 25 quarries in the evacuation zones, up to 122,400 becquerels of radioactive caesium was found at one that has been closed since the nuclear crisis broke out on 11 March 2011. In one quarry, that is still operational 5,170 becquerels per kilogram was found. Inspections were done at some 150 of the 1.100 construction sites, where the gravel form the Namie-quarry was suspected to be used. At 27 locations the radioactivity levels were higher than the surrounding area. On 6 May 2012 it became known that according to documents of the municipal education board