In 2021, approximately 20 % of French people in mainland France, or some 12 million people, have received at the tap, “regularly or occasionally, water that does not comply with quality criteria”, according to data collected by Le Monde from regional health agencies, water and prefectures. However, should this prevent us from consuming it?
Water is the safest and most controlled food in France. And yet, the pesticides and the molecules resulting from the degradation of the latter would have serious consequences on the quality of the water. Should we be worried about this news? Is drinking water with traces, even minimal, of pesticides dangerous for your health?
Figures “probably” underestimated
For Julie Mendret , lecturer at the University of Montpellier and specialist in water treatment, the results made public Thursday, September 22 are “a stone in the pond”. “Analytical methods are progressing. The more we look, the more we will find [pesticides in the water]. We even find banned pesticides…”, she laments.
In December 2020, the General Directorate of Health extended the fields of research for pesticides in drinking water. Result: the 6% of French people concerned in 2020 rose to 20% in 2021. It was “predictable”, estimates Mickaël Derangeon , vice-president of Atlantic’eau , public service for the distribution of drinking water in the Loire- Atlantique, and lecturer at Nantes University in physiology, the study of the functioning of living organisms. These new results are “probably below reality”, he adds.
There are two types of drinking water control. First, that of the Regional Health Agencies (ARS), which each determine a list of molecules to be searched for. Drinking water network managers also carry out self-checks.
Everywhere in France, pesticides deemed potentially dangerous must not exceed the threshold of 0.1 microgram per liter (or 0.3 microgram for some) and their sum must not exceed 0.5 microgram/litre. Thresholds set in 2007, without certainty about the reality of the risks.
To set health standards, explains Le Monde, the National Agency for Food, Environmental and Occupational Health Safety (Anses) needs studies. These do not yet exist for all pesticides.
As many pesticides in 1 kg of celery as in 500,000 liters of water
“The long-term health effects of exposure to low doses of pesticides are difficult to assess,” writes the Ministry of Health on its website .
So should we be afraid to drink tap water? However, the quantities of pesticides present in tap water should be put into perspective, explains Mickaël Derangeon . “The scale is different in food. Conventional foods [not from organic farming] can legally contain in 1 kg up to 500,000 times more pesticides than a liter of water. In 1kg of celery, you can legally have as many pesticides as in 500,000 liters 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 in life, for example when you are a baby or pregnant”, adds Mickaël Derangeon , referring in particular to the effects on the development of the brain of some babies. ” We have the scientific evidence, but there is no public health response ,” he laments.
How do pesticides end up at the tap?
So what to do? We must first understand how pesticides end up in our faucet. Spreading is the primary cause of pesticide infiltration into the soil. These molecules are also found in the rain and, finally, in our treatment plants through our food.
Once in the environment, the pesticide molecule can change on contact with humidity or with changes in temperature, for example. This modified molecule is called the metabolite. It is he who is found in tap water.
Bottled water, the solution?
So should we drink bottled water? “I drink tap water. When I buy bottled water, I don’t know how long it’s been there, maybe in the sun! “, testifies the vice-president of Atlantic’eau . Several studies have also demonstrated the presence of microplastics in these bottled waters. “So it’s not a solution”, evacuates Mickaël Derangeon .
Julie Mendret also highlights the environmental impact of bottled water. “It would be a disaster if everyone started drinking bottled water”, explains the one who published an article this summer in The Conversation defending the consumption of tap water, “safer than water in bottle “.