Caesium out of the body relatively quickly in sweat and urine. The remaining 90% has a biological half-life between 50 and 150 days. Radiocaesium follows potassium and tends to accumulate in plant tissues, including fruits and vegetables. Plants vary widely in the absorption of caesium, sometimes displaying great resistance to it. It is also well-documented that mushrooms from contaminated forests accumulate radiocaesium (caesium-137) in the fungal sporocarps. Accumulation of caesium-137 in lakes has been a great concern after the Chernobyl disaster. Experiments with dogs showed that a single dose of 3.8 millicuries (140 MBq, 4.1 μg of caesium-137) per kilogram is
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