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
Fukushima Daiichi nuclear disaster was still higher in Tokyo compared to other cities in Japan. Trace amounts of radioactivity, including iodine-131, caesium-134, and caesium-137, were widely observed. Between 21 March and mid-July, around 27 PBq of caesium-137 (about ) entered the ocean, with about 82 percent having flowed into the sea before 8 April. However, the Fukushima coast has some of the world's strongest currents and these transported the contaminated waters far into the Pacific Ocean, thus causing great dispersion of the radioactive elements. The results of measurements of both the seawater and the coastal sediments led to the supposition that the consequences of