Up to 12 million people in France have drunk tap water that contains pesticide levels above the acceptable quality threshold, it has emerged this week.
A report by FranceInfo and Le Monde yesterday (September 22), which was also highlighted on the Complément d’enquête programme on France 2, revealed the number, which equates to around 20% of the population.
In Brittany, the percentage is estimated to be as high as 43% of the population affected.
Across France, pesticides that are judged to be potentially dangerous must not exceed the threshold of 0.1 micrograms per litre (or 0.3 micrograms for some), and the total must not exceed 0.5 micrograms per litre. These thresholds were set in 2007.
Health norms are usually set after studies by health and food safety agency l’Agence nationale de sécurité sanitaire de l’alimentation, de l’environnement et du travail (Anses). But studies do not yet exist for all pesticides.
Numbers ‘probably’ underestimated
Water treatment specialist at the University of Montpellier, Julie Mendret, told Ouest France that the numbers were “a drop in the ocean”. She said: “Analysis methods are developing. The more we look, the more we will find [pesticides in water]. We are even finding banned pesticides.”
In December 2020, health authority la Direction générale de la Santé extended its research of pesticides in water, and found that the percentage of people in France who were affected had grown from 6% in 2020 to 20% in 2021.
The results are “predictable”, said Mickaël Derangeon, vice-president of Loire-Atlantique public drinking water distribution service Atlantic'eau, and physiology lecturer at Nantes University.
They are even "probably below reality", he added.
Drinking water in France is monitored by two different checks. The first comes from regional health authorities the Agences régionales de Santé (ARS), which determines a list of molecules to research.
Ms Mendret said: “The limits are determined according to the pesticides used locally.” For example, in Corsica, 30 molecules are searched for, compared to 386 in Île-de-France.
The managers of drinking water networks also carry out their own checks, with many going above and beyond the minimum checks required.
For example, Mr Derangeon said: “In Loire-Atlantique, we go further [and] we publish the results. We also carry out tests, so we take the water and put it on bacteria, human cells, fungi... to see the effect on living things.
“So far, we haven't seen any impact, which is reassuring. But we cannot certify that there is no risk to pregnant women or babies.”
Are pesticides at worrying levels in French tap water?
Yes and no, experts say.
The health ministry has said: "The long-term health effects of exposure to low doses of pesticides are difficult to assess.”
Meanwhile, Mr Derangeon has said that while tap water is still safe to drink, "water is the basis of life. It is not normal to find pesticides in it. Pesticides are used to kill insects and plants".
However, he said that pesticide levels in water are far lower than those found in food.
He said: "The scale is different in food. Conventional food [not organically grown] can legally contain up to 500,000 times more pesticides in 1kg, than a litre of water. In 1kg of celery, you can legally have as much pesticide as in 500,000 litres of water.
"But even in small amounts, pesticides can have consequences. The risk with water is exposure over the long term or at certain times of life, for example when you are a baby or pregnant.”
He has said that while “the scientific evidence” is there, “there has been no public response [yet]”.
In its report, Le Monde said that “the breaching of thresholds does not necessarily mean there is a risk to health”.
However, Arnaud Clugery, director and spokesman for Eau et Rivières de Bretagne, has taken a harsher stance.
He said: “ESA-metolachlor is a pesticide by-product from a maize weed killer. Who can think today that a chemical molecule designed to kill living organisms is safe in drinking water?
What are water bodies and experts calling for in response?
Mr Clugery, in Brittany, has said: "We are asking for the protection of water catchment areas and not just the protection perimeters.”
Brittany was shown to have the highest pesticide levels in the country.
Eau et Rivières de Bretagne has also published a plea for pesticide-free drinking water on its website.
It reads: "We demand that the public authorities become truly aware of the widespread contamination of water by pesticides and that ambitious measures are finally taken to put an end to the large-scale use of these toxic substances.”.
So do we need to drink bottled water instead?
Not necessarily, except perhaps if you are pregnant or vulnerable.
Despite his concerns, Mr Derangeon said that he still drinks tap water, mainly because “when I buy bottled water, I don’t know how long it has stood there for, maybe in the sunshine”. He also said that some studies have shown the presence of microplastics in bottled water, “so it’s not a solution”.
Ms Mendret has also said that “it would be catastrophic if everyone started drinking bottled water”, because of the plastic bottle waste that would ensue.
However, she said in an article over the summer that in intensive farming regions, “we should temporarily stop drinking tap water”. She used the example of the village of Castellet in Var, where pesticide levels were found to be at 0.7 micrograms per litre. Locals are now advised not to drink the tap water.
Read more: Tap water more safe to drink in urban areas
Yet, Mr Derangeon said that the situation was being monitored. He said: “Water is the most tested element in France.”
He said that people who really want to switch to bottled water should only use water in glass bottles, and recycle or reuse them.