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
Accident rating of the Fukushima Daiichi nuclear disaster radioactive material have also been released into ground and ocean waters. Measurements taken by the Japanese government 30–50 km from the plant showed caesium-137 levels high enough to cause concern, leading the government to ban the sale of food grown in the area. Tokyo officials temporarily recommended that tap water should not be used to prepare food for infants. In May 2012, TEPCO reported that at least 900 PBq had been released "into the atmosphere in March last year [2011] alone". Several of the plant's workers were severely injured or killed by the disaster conditions resulting from the earthquake. There