Effects of the Chernobyl disaster of caesium-137 in Europe) While the IAEA/WHO and UNSCEAR considered areas with exposure greater than 40,000 Bq/m, the TORCH report also included areas contaminated with more than 4,000 Bq/m of Cs-137. The TORCH 2006 report "estimated that more than half the iodine-131 from Chernobyl [which increases the risk of thyroid cancer] was deposited outside the former Soviet Union. Possible increases in thyroid cancer have been reported in the Czech Republic and the UK, but more research is needed to evaluate thyroid cancer incidences in Western Europe". It predicted about 30,000 to 60,000 excess cancer deaths, 7 to 15 Times greater
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