What caused radiation spike in north west China: North Korea, Europe or something else?
Levels of iodine-129 in capital of Shaanxi province peaked two days after hydrogen bomb test 2,000km away
Radiation levels in a Chinese city nearly 2,000km from a North Korean nuclear test site spiked following Pyongyang’s latest and most powerful nuclear weapons test in September, according to Chinese scientists.
However, the spike in iodine-129 levels Xian was probably not related to the detonation of a 100-kilotonne hydrogen bomb in a tunnel at the Punggye-ri nuclear test site on September 3 and was more likely to have originated in Europe, they said.
The spike was recently declassified by the Chinese Academy of Sciences, prompting heated discussion among researchers about its possible cause, with some disputing the Europe theory.
From September 3 to 11, levels of iodine-129 in Xian, capital of Shaanxi province in northwestern China, jumped to at least 4.5 times the average, according to readings picked up by instruments at the academy’s Institute of Earth Environment, which is based in the city.
Iodine-129 is an isotope of the element iodine that rarely occurs in nature. It is mostly produced by man-made fission and is closely monitored around the world as evidence of nuclear weapons tests or nuclear accidents.