Environmental radioactivity part of the Chernobyl release was the caesium-137, this isotope is responsible for much of the long term (at least one year after the fire) external exposure which has occurred at the site. The caesium isotopes in the fallout have had an effect on farming. A large amount of caesium was released during the Goiânia accident where a radioactive source (made for medical use) was stolen and then smashed open during an attempt to convert it into scrap metal. The accident could have been stopped at several stages; first, the last legal owners of the source failed to make arrangements
Radiation effects from the Fukushima Daiichi nuclear disaster of marine life that is fished in the coastal waters off Fukushima. Despite caesium isotopic concentration in the waters off of Japan being 10 to 1000 times above concentration prior to the accident, radiation risks are below what is generally considered harmful to marine animals and human consumers. A year after the disaster, in April 2012, sea fish caught near the Fukushima power plant still contain as much radioactive Cs and Cs compared to fish caught in the days after the disaster. At the end of October 2012 TEPCO admitted that it could not exclude radioactivity releases into the ocean,