A trace of radioactive Iodine-131 of unknown origin was in January detected over large areas in Europe. Since the isotope has a half-life of only eight days, the detection is a proof of a rather recent release.Where the radioactivity is coming from is still a mystery.
The air filter station at Svanhovd was the first to measure small amounts of the radioactive Ionide-131 in the second week of January. The station is located a few hundred metres from Norway’s border to Russia’s Kola Peninsula in the north.Soon, the same Iodine-131 isotope was measured in Rovaniemi in Finnish Lapland. Within the next two weeks, traces of radioactivity, although in tiny amounts, were measured in Poland, Czech Republic, Germany, France and Spain.
Iodine-131 (131I), is an important radioisotope of iodine discovered by Glenn Seaborg and John Livingood in 1938 at the University of California, Berkeley. It has a radioactive decay half-life of about eight days. It is associated with nuclear energy, medical diagnostic and treatment procedures, and natural gas production. It also plays a major role as a radioactive isotope present in nuclear fission products, and was a significant contributor to the health hazards from open-air atomic bomb testing in the 1950s, and from the Chernobyl disaster, as well as being a large fraction of the contamination hazard in the first weeks in the Fukushima nuclear crisis. This is because I-131 is a major fission product of uranium and plutonium, comprising nearly 3% of the total products of fission (by weight). See fission product yield for a comparison with other radioactive fission products. I-131 is also a major fission product of uranium-233, produced from thorium. https://en.wikipedia.org/wiki/Iodine-131