So we say here that it never happened because the cloud was blocked at the border.
It's now an historical reference of government lying to our face without second thoughts.
If I may ask: aren't there mechanisms that prevent the French State from lying so blatantly to its citizenry? How was this ultimately found out?
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...
We are still far from knowing everything about danger from radioactive fallout, but there has been a lot of research since then.
Of course, neither of them were ever anywhere near Chernobyl...
>The IRSN said that the concentrations of ruthenium 106 in the air that have been recorded in Europe were of no consequence for human health and the environment.
I presume that if it had been serious they (a) would have been able to detect it more quickly, since more serious means more of it, and (b) would have immediately announced it more widely rather than doing a full investigation first.