Drinking water contaminated with pesticide banned from 2020

The alert was triggered by Switzerland, where every third measuring station is concerned. An ANSES report published on Thursday shows that drinking water in France is also largely contaminated with residues of chlorothalonil, a fungicide sold by agrochemical giant Syngenta and banned in France from 2020.

Every three years, the National Health Security Agency’s hydrology laboratory in Nancy conducts campaigns to measure the presence of chemical compounds in drinking water. emerging “, which are still or little searched during regular checks. Thus, this latest report analyzes the presence of more than 157 pesticides and pesticide metabolites, in other words, components resulting from the breakdown of phytopharmaceuticals, which exist in a very wide variety, but which experts have only recently been able to measure. The researchers also assessed the presence of 54 explosive residues (mostly from World War I-era weapons emplacements) and the presence of the solvent 1,4-dioxane. A campaign carried out in every French department, including abroad, which made it possible to collect more than 136,000 results through raw or purified water samples.

Conclusion. of the 157 pesticides tested, 89 were detected at least once in raw water and 77 times in treated water. But two compounds were quantified in more than 50% of raw or treated water samples, and “One specific case stands out,” indicates ANSES to the chlorthalonyl R471811 metabolite. first” it is the pesticide metabolite most commonly found in more than one of the two samples “; on the other hand, ” this results in exceeding the quality limit in more than one out of three samples “.

This quality limit, set in 2007 at 0.1 µg/litre for each relevant metabolite, however, has “ has no health significance “, according to the General Directorate of Health. If more information is available, DGS suggests using the German values ​​set at 3 µg/litre.. ” Our results are all below », says Christophe Rosin, head of the water chemistry department of the ANSES hydrological laboratory. “The water sampled and analyzed is therefore non-compliant but does not pose any health risk.“, the Ministry of Ecological Transition assured on Friday.

“Precautionary principle”.

Banning chlorothalonil in 2019, the European Union classified it as a category 1B carcinogen (potentially carcinogenic to humans). it is assumed “). Then he said: It has not been possible to date to confirm that the presence of chlorothalonil metabolites in groundwater will not have an adverse effect on human health or have an unacceptable effect on those waters. “, or on the fauna and flora living in them. In a conclusion published last year, ANSES agrees with the opinion of the European Food Safety Authority (EFSA). given the lack of data to demonstrate that the metabolite chlorothalonyl R471811 does not share the mode of action of the main active ingredient leading to renal tumors in rats or mice. As a precautionary measure, the French agency therefore considered that this metabolite should be considered as ” appropriate and should be subject to the same precautions as the active substance.

” In general, we have less information about the effects of metabolites than about the effects of the parent molecules, which motivates this precautionary principle. notes Christophe Rozin. These are molecules that we weren’t looking for three or four years ago, so we don’t know the level of water pollution in recent years. [ni le degré d’exposition des consommateurs, ndlr]. This report does not represent an alarm, it is a T hour snapshot, monitoring should continue. »

In any case, the ANSES study indicates that “ Depending on their properties, some pesticide metabolites can persist in the environment for several years after the active substance from which they are derived has been banned. “. It states, however, that it does not exceed ” maximum sanitary values Observed (Vmax*, material specific safety limit).

The results of this work have been passed on to health authorities who will have to ” complete their health surveillance programs in order to better assess population exposure levels. “What about ARS health control?From 2023, the program will gradually integrate chlorothalonil and its metabolites in connection with increasing the skills of laboratories approved for the sanitary control of water to ensure reliable results during accreditation.DGS confirms. “ It will happen gradually »predicts Christophe Rozin, because it will take several months for laboratories to acquire the necessary technology to track this molecule.