Nuclear fuels like Uranium-239 undergoing fission split apart and one of the products is I-131
In the comments section of the article I posted, I see someone’s theory re source of I-131 in Europe is Fukushima. Won’t have time to check out the video they post but here it is if anyone is interested:
BEGINNING OF NOV: high radiation (620 mSv/h) at reactor 3, Fukushima Daiichi
NOV 2: detection of Xenon 133,135 at reactor 2, Fukushima Daiichi
NOV 5: many minor health effects (e.g., eye itching) reported via tweets in Tokyo, wind came from the North
NOV 6: air with radioactivity is brought from the North to Tokyo
NOV 11: radioactivity in Europe
Reference: http://fukushima.over-blog.fr/article-iode-radioactif-sur-l-europe-evenement-nucleaire-en-cours-88519209.html
Simulation: http://www.youtube.com/watch?v=08dcG-ibYrY&feature=player_embedded