Caesium-137 or approximately 44 μg/kg) of caesium-137 (and 950 to 1400 rads), they die within 33 days, while animals with half of that burden all survived for a year. Accidental ingestion of caesium-137 can be treated with Prussian blue, which binds to it chemically and reduces the biological half-life to 30 days. Caesium-134 and caesium-137 were released into the environment during nearly all nuclear weapon tests and some nuclear accidents, most notably the Chernobyl disaster and the Fukushima Daiichi disaster. As of 2005 and for the next few hundred years, caesium-137 is the principal source of radiation in the zone of
Radiation effects from the Fukushima Daiichi nuclear disaster continue to monitor for long-term mental effects as they may not be present right away. On 24 May 2012, more than a year after the disaster, TEPCO released their estimate of radioactivity releases due to the Fukushima Daiichi Nuclear Disaster. An estimated 538.1 petabecquerels (PBq) of iodine-131, caesium-134 and caesium-137 was released. 520 PBq was released into the atmosphere between 12 and 31 March 2011 and 18.1 PBq into the ocean from 26 March to 30 September 2011. A total of 511 PBq of iodine-131 was released into both the atmosphere and the ocean, 13.5 PBq of caesium-134 and 13.6