When thyroid cancers started increasing in south east France, what was a rumor (imagine a cloud consciously avoiding France...) begins to be a proof that leaded to an investigation.

More infos (in English) here https://www.expatica.com/fr/news/country-news/France-hid-inf...

I'm afraid I don't know how it ended (I wasn't in France at that time)

Edit : it seems the case was dismissed (as it is often in France when government is implicated...) https://amp.rfi.fr/en/asia-pacific/20110907-french-court-dis...