Radiation effects from the Fukushima Daiichi nuclear disaster times the safety limit, Professor Yasuyuki Muramatsu at the Gakushuin University urged detailed checks on wild plants and animals. Radioactive caesium in soil and fallen leaves in forests in his opinion would be easily absorbed by mushrooms and edible plants. He said that wild animals like boars were bound to accumulate high levels of radioactivity by eating contaminated mushrooms and plants. The professor added that detailed studies were on wild plants and animals. Across Europe the Chernobyl-incident had likewise effects on wild fauna and flora. The first study of the effects of radioactive contamination following the Fukushima Daiichi nuclear disaster
Caesium-137 limits, but some areas that are currently less than 5 mSv/year may be decontaminated, allowing 22,000 residents to return. Caesium-137 in the environment is substantially anthropogenic (human-made). Caesium-137 is produced from the nuclear fission of plutonium and uranium, and decays into barium-137. Before the construction of the first artificial nuclear reactor in late 1942 (the Chicago Pile-1), caesium-137 had not occurred on Earth in significant amounts for about 1.7 billion years. By observing the characteristic gamma rays emitted by this isotope, one can determine whether the contents of a given sealed container were made before or after the first atomic