A study by ANSES shows that a third of the drinking water consumed in France is contaminated by a herbicide banned since 2020. The government ensures that there is “no health risk”.
A third of the drinking water consumed in France is contaminated by a pesticide, chlorothalonil, which has been banned since 2020 in France, according to a study of the National Agency for Food, Environmental and Occupational Health Safety (Anses) published Thursday. The government ensures this Friday that more frequent checks of this product will be carried out.
• What pesticides were discovered?
Among the 157 pesticides evaluated in the survey, the ANSES report particularly points the finger at the presence in water of the metabolite of chlorothalonil R471811. It is a component resulting from the degradation in the environment of the pesticide concerned.
Chlorothalonil R471811 is a fungicide marketed by the multinational Syngenta. Banned in France since 2020, it has been widely used in agriculture for 50 years. In 2017, 39 products, ranging from wheat to tomatoes and carrots, were still sprayed in France with this pesticide, according to ANSES.
In addition, another pesticide residue, metolachlor ESA, has been identified. It is a herbicide used in particular to weed corn crops.
• What is the extent of the contamination?
The metabolite of chlorothalonil R471811 was found “in more than one out of two samples”, according to the study, which leads to exceedances of the quality limit, set at 0.1 micrograms per litre, “in more than one out of three levies”.
Concerning metolachlor ESA, it is present in more than half of the samples. Less than 2% of them exceed the management value of 0.9 milligrams per liter defined for irrelevant metabolites.
The results are still partial, but reveal for the moment that certain territories are more concerned than others. The Paris basin, the Loire-Atlantique, but also many municipalities in the Oise are particularly affected, when the South-East and Corsica are more spared.
These rates remain lower than the maximum health values established in France or even the health values established in Germany of a maximum of 3 micrograms per liter, also recalls Christophe Rosin, head of the water chemistry unit at the ANSES hydrology laboratory in Nancy, in Release.
• Why its presence in the water despite the ban?
According to ANSES, the results of the study show that “certain pesticide metabolites may remain present in the environment for several years after the banning of the active substance from which they originated”. Syngenta, for its part, assures AFP that it takes the safety of its products “very seriously”.
This phenomenon is not surprising for associations. Certain pesticide metabolites may remain present in the environment for several years after the banning of the active substance from which they originated.
“Pesticides do not disappear with a spoon,” abounds Dominique Le Goux, of the Water and Rivers Association of Brittany.
• Should we be worried?
Chlorothalonil is a product which “should be classified as a category 1B carcinogen”, that is to say a “suspected” carcinogen, according to conclusions made by the European Food Safety Authority (EFSA).
In fact, studies indicate that “kidney tumors in rats and mice” have been found in studies with chlorothalonil. Last February, ANSES said it wanted to ban the main uses of this molecule.
However, ANSES emphasizes that the presence of the pesticides detected does not necessarily mean that there is a danger, the levels measured remaining below the maximum health values.
“The fact of being beyond the quality criteria does not necessarily induce a health risk”, confirms in The world Régis Taisne, head of the water cycle department at the National Federation of Concessioning and Regulated Communities (FNCCR), while specifying that many unknowns remain and that “water stakeholders would still like to know if this molecule is actually problem”.
• What consequences?
According to the FNCCR, “elimination of this metabolite in drinking water is possible”, but “would require major investments for water services involving a significant increase in the price of water”.
The executive wants to be reassuring. The Ministry of Ecological Transition recalls this Friday that “the transitory health value allowing to prevent a health risk (is) of 3 milligrams per liter”, is higher than the rates detected.
“The water sampled and analyzed is thus non-compliant but does not present a health risk”, he concludes.
The government nevertheless indicates that it remains “vigilant” and ensures that, as a precaution, “more regular measurements” of the product will be put in place this year in order to assess the evolution of the presence of chlorothalonil and its metabolites in the ‘water.