The prefecture of the Paris region denied on Saturday that tap water in the French capital presents "any risk for public health" and described as "fake news" social media rumours claiming the water is polluted with tritium, a nuclear element.
"The levels [of tritium in the water] do not pose a risk to public health. Tap water can be drunk without restriction", the Paris prefecture wrote on Twitter.
The rumours started earlier this week after French radioactivity watch group ACRO published a report claiming that six million people, in the Paris region as well as the Loire and Vienne areas, drink tap water contaminated with tritium.
The report is based on data from the Health ministry and includes a map of the average tritium levels in tap water across France. They are higher in the mentioned regions, but "no value exceeds the quality critera of 100 Ba/L introduced by the authorities", the report adds.
Local media reported on ACRO's findings but did not always make clear that the levels of tritium do not pose a threat to health.
However, rumours started to grow on social media after a message claiming to be written by a Paris nurse went viral on Whatsapp, AFP reported. It warned of "titanium presence" in Paris tap water and mentioned a prefectural decree, which the Paris prefecture denied ever existed.
"Drinking Paris water does not pose a threat to health, tritium is present in infinitesimal doses in the water, without any risk in short, medium or long term", the Twitter account for the Paris water company wrote on Twitter.
The quality reference for tritium levels in France is set at 100 Bq/L, which is much lower than the reference of 10,000 Bq/L recommended by the World Health Organisation, Eau de Paris said in a statement.
"The quantities measured in Paris water are much lower than these levels", the statement said.