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 radioactivity before consumption. Also in July citizens groups reported that a survey of soil at four places in the city of Fukushima taken on 26 June proved that all samples were contaminated with radioactive caesium, measuring 16,000 to 46,000 becquerels per kilogram and exceeding the legal limit of 10,000 becquerels per kg, A study published by the PNAS found that caesium 137 had "strongly contaminated the soils in large areas of eastern and northeastern Japan." After the find of 8,000 becquerels of caesium per kilogram in wild mushrooms, and a wild boar that was found with radioactivity amounts about 6