It is not by changing the thermometer that you bring down the fever. In thousands of municipalities, tap water, hitherto polluted by high levels of pesticides, could suddenly become compliant. Not because their quality has improved, but because a new vigilance threshold could come into effect.
On September 30, ANSES (National Agency for Food, Environmental and Occupational Health Safety), specializing in the subject, has published new notices modifying the status of two molecules, frequently detected in French tap water. These are ESA-metolachlor and NOA-metolachlor, two metabolites (i.e. derivatives) of S-metolachlor, a herbicide widely used in maize cultivation.
>> Read also: What we know about pesticide residues in tap water in thousands of municipalities (and uncertainties about their toxicity)
Until then, these two metabolites were considered by ANSES as “relevant”, in other words as being able to represent a risk for human health. Tap water in a municipality is declared “non-compliant” when such a molecule is detected at more than 0.1 micrograms per liter (μg/L). But the agency now classifies them as “irrelevant”which implies that their presence in tap water is tolerated with a higher threshold: it goes from 0.1 to 0.9 μg/L. Implementing decrees must be published for this new criterion to really come into force.
This regulatory game could have far-reaching consequences, given that theESA-metolachlor is one of the most frequently found molecules in tap water. Between January 2021 and July 2022, the two molecules in question had been detected at more than 0.1 μg/L in 6,858 samples. But if we use the new threshold of 0.9 mg/L, there are only 210 exceedances. That is 32 times less, according to the calculations of franceinfo, carried out in the wake of work in collaboration with the magazine “Complément d’Enquête” in September, and publications of the World on the subject. According to the Future Generations association, with such a threshold, “97% of the water distributed declared non-compliant following an overrun of the quality value for theESA-metolachlorwould become compliant”. A “sleight of hand”according to her.
How to explain this change of label? ANSES previously considered ESA-metolachlor and NOA-metolachlor as “relevant”, therefore potentially dangerous, because the data provided by Syngenta, the manufacturer marketing the pesticide in question, did not make it possible to rule out the genotoxicity (the ability to affect DNA) of the two molecules. The precautionary principle applied. But at the end of 2021, Syngenta submitted new studies concerning the genotoxicity of the two metabolites. After examining them, ANSES considered that these recent data made it possible to remove any doubt on this point.
On the other hand, several observers warn: there is still a lack of data to know the dangerousness of these molecules concerning reproduction, their carcinogenic aspect or their potential for endocrine disruption. On these three points, the precautionary principle does not apply. “We regret this decision.judge Pauline Servan, of Génération futures, contacted by franceinfo. While we do not have data for these three criteria, ANSES is able to say that these metabolites do not pose a risk to consumers. However, a molecule can be carcinogenic without being genotoxic. And vulnerable people are potentially exposed to it on a daily basis.”
Another point of criticism: ANSES conducts its assessments based on studies provided by manufacturers. “It is the pesticide producers who provide new data to invalidate the fact that their molecule is dangerous. They are both judges and stakeholders. How can we regain the confidence of citizens in the consumption of drinking water? catastrophic from a communication point of view”points out Mickaël Derangeon, vice-president of Atlantic’Eau, water union in Loire-Atlantique.
Contacted by franceinfo, ANSES had not answered our questions at the time of publishing this article. Nearby Worldthe agency explained (article reserved for subscribers)”having scrupulously followed the evaluation scheme that it established in 2021 to assess the relevance, or non-relevance, of pesticide metabolites”.
But this file could experience a new twist in the coming months. S-metolachlor, the pesticide from which the two metabolites declassified by ANSES are derived, is currently undergoing a reassessment at European level. And the French health agency is clear on the subject, including in its opinions: the relevance of the metabolite could again be modified. “If S-metolachlor were classified as an endocrine disruptor, it would be necessary to reassess the classification of relevance for the metabolite ESA”note the authors.
In the meantime, local actors fear a reversal of years of awareness-raising and expensive investments by communities to restore water quality. “In the field, we are already having trouble getting people to admit that there is a public health problem, deplores Mickaël Derangeon. And there, we are told that all the efforts for several years have been for nothing, because there is no longer any risk.
You can also consult our search engine to find out if excesses in ESA-metolachlor and NOA-metolachlor above the threshold of 0.9 μg/L have been observed in your municipality.