Do you regularly drink water from your tap? Know that in some corners of France, it contains abnormal amounts of pesticide metabolites. This is at least the observation made by franceinfo (source 1) and The world (source 2) this Thursday, September 22, 2022, the day of the broadcast of an issue of Further investigation (France 2), entitled: “Is tap water (really) drinkable?”. The media also report malfunctions in monitoring the quality of the drinking water network. Should we be worried about this news? What can be the health consequences?
Metabolites of pesticides in tap water: one in four municipalities would be concerned
The metabolites are molecules resulting from the degradation of pesticides. Concretely, when they diffuse into the environment, pesticides fragment and recombine. Each phytosanitary product can thus generate several new molecules which infiltrate the soil and are thus likely to contaminate water resources.
The observation made by Further investigation is instructive: based on sanitary analyzes of drinking water, the teams have discovered that in 2021, pesticides were detected above the quality limit in almost one out of four French municipalities.
The investigation of Worldit, based on data collected from regional health agencies, water agencies or prefectures, reveals that in 2021:
About 20% of French people in mainland France – some 12 million people – have received water from the tap, regularly or occasionally, that does not meet quality criteria.
Some regions seem more particularly affected, remarks The world, as Hauts-de-France (65% of the population was affected – regularly or occasionally – by drinking water non-compliance in 2021), theBrittany (43%), the Great East (25.5%) and the Pays de la Loire (25%). However, within the same region, the situation can vary greatly from one department to another.
What are the health risks ? What are the regulations?
Are these residues dangerous to health? Hard to know.
It is considered that a metabolite content greater than 0.1 µg/L makes the water non-compliant with the quality requirements. However, “non-compliant” water is not necessarily considered non-edible toxic water, say the authorities. So that water is no longer distributed on the network at all, a second threshold must be exceeded, called “Vmax” (maximum health value).
Problem ? This Vmax has not been established for all the molecules, for lack of sufficient data. “In the absence of TRVs (toxicological reference values, editor’s note) it may happen that ANSES is not able to provide Vmax“, recognizes the Agency on its site. Many of these molecules, and their effects, therefore remain unknown.
The long-term health effects of exposure to low doses of pesticides are difficult to assess, recognizes the Ministry of Health.
“In order to manage local situations pending a maximum value, determined by ANSES, an instruction from the Ministry of Health published on June 15, 2022 determined a transient health value of 3µg / L of water”, indicates the ARS of Hauts-de-France. Since September 15, the tap water of nearly 105 municipalities in the region has thus been placed under reinforced surveillance.
Should we be concerned about the presence of these pesticide metabolites?
A number of experts interviewed in the context of these surveys relativize on one point: the concentration of these residues in tap water is disproportionate to the levels found directly in non-organic foods. Indeed, in one kilo, conventional food (not from organic farming) can legally contain up to 500,000 times more pesticides than in one liter of water. In other words, legally, in 1 kg of celery, you can find as many pesticides as in 500,000 liters of water.
However, the consequences of exposure to pesticides, even in small quantities, are not yet known. Scientists are especially concerned its impact during pregnancy or childhood.