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 tests were available. On 16 November 630 becquerels per kilogram of radioactive caesium was detected in rice harvested in the Oonami district in Fukushima City. All rice of the fields nearby was stored and none of this rice had been sold to the market. On 18 November all 154 farmers in the district were asked to suspend all shipments of rice. Tests were ordered on rice samples from all 154 farms in the district. The result of this testing was reported on 25 November: five more farms were found with caesium contaminated rice at a distance of 56 kilometers from