What is the impact of water quality on our health?

In 2024, at least 19.2 million French people consumed water that did not meet regulatory quality standards, according to data from the Ministry of Health. Tap water is nonetheless the most controlled food in France. This paradox is explained by the emergence of new contaminants, many of which were not tested until recently, and by the limitations of a regulatory framework under revision. The impact of water quality on health is now at the heart of major scientific and institutional work.

Water quality and health: an increasingly documented link

The quality of drinking water directly conditions the daily exposure of the population to a wide range of chemical and biological substances. Consumed in an average amount of 1.5 to 2 liters per day, tap water is a vector of chronic exposure to pollutants whose cumulative effects are the subject of increasing studies. Recent data reveal the extent of the problem: pesticides have been detected in 97% of French water monitoring stations, and trifluoroacetic acid (TFA), a PFAS resulting from the degradation of certain pesticides, has been identified in 92% of the samples analyzed between 2023 and 2025 by ANSES. In response to this situation, filter brands like Pureva offer domestic solutions aimed at reducing exposure to the main chemical contaminants present in tap water. The extensive campaign by ANSES published in December 2025, which constitutes to date the most comprehensive assessment ever conducted in France on PFAS in raw and distributed waters, confirms the urgency of enhanced monitoring.

What contaminants, what health risks?

Contaminants in drinking water that may affect human health fall into several categories, with distinct toxicological profiles. The state of scientific knowledge, although still incomplete for some recently identified molecules, allows us to establish the documented effects as follows. PFAS (per- and polyfluoroalkyl substances): this family of several thousand chemical compounds is associated, according to work by ANSES and the European Food Safety Authority (EFSA), with effects on the immune system, thyroid function, fertility, and the liver. Some PFAS are classified as possible carcinogens by the International Agency for Research on Cancer (IARC). TFA (trifluoroacetic acid): a degradation metabolite of several pesticides and itself a PFAS, TFA is defined by the European Commission as a substance of “concerning toxicity”. Industrial studies associate it with liver effects, reduced sperm quality, and effects on the thyroid system. Its potential classification as a reprotoxicant is under evaluation. Nitrates: at high concentrations, nitrates induce methemoglobinemia in infants, reducing the blood’s ability to carry oxygen. In adults, prolonged exposure is associated in some studies with an increased risk of digestive cancers, although this link is still the subject of scientific debate. Pesticides and metabolites: classified as endocrine disruptors for a large number of them, these compounds can interfere with hormonal and reproductive systems, as well as neurological development in children. 71% of pesticide metabolites at risk of contaminating groundwater are currently not monitored in France, according to an interministerial report of June 2024. Lead (old pipes): a proven neurotoxin, lead presents a particularly well-documented risk in children, for whom even low chronic exposure can affect cognitive development. The presence of lead in water is related to the condition of the pipes and not to the source, making it an unevenly distributed risk depending on the age of the infrastructure.

What the regulatory framework says in 2025

European and French regulations have significantly evolved in recent years, under pressure from scientific data and consumer associations. The European directive 2020/2184 on drinking water, transposed into French law in 2022, mandates compulsory monitoring of 20 PFAS in distributed water starting January 12, 2026, with a quality threshold set at 0.1 µg/L for the sum of these substances. However, this limit is questioned by part of the scientific community, who consider it insufficiently protective in view of the documented cumulative effects. In France, PFAS law no. 2025-188 of February 27, 2025, provides for the publication of an annual regional report on the quality of PFAS in distributed water. TFA, whose presence is almost universal, is not yet included in the 20 regulated PFAS: the reference health values expected from ANSES are not expected before the end of 2026.

Who are the most vulnerable groups?

Exposure to water contaminants does not present the same level of risk for the entire population. Several groups are the focus of increased health vigilance. Infants and young children are particularly exposed to nitrates, lead, and endocrine disruptors, due to their physiological immaturity and the proportion of water consumed relative to their body mass. Pregnant women are concerned about the potential reprotoxic effects of TFA and certain PFAS on fetal development. Immunocompromised individuals are more sensitive to microbiological contaminants. Finally, people with kidney or liver pathologies have reduced capacities to eliminate these substances, increasing the risk of accumulation.

Reducing exposure: what concrete solutions?

The first step is to know the quality of the water distributed in one’s community. Platforms atlasante.fr and dansmoneau.fr provide access to the results of sanitary control by distribution network for the main regulated contaminants. Home filtration is a recognized complementary measure. Activated carbon filters effectively reduce pesticide residues, chlorine, and certain metabolites. Reverse osmosis systems are more effective on PFAS, nitrates, and heavy metals, at the cost of more complex installation and higher water consumption during the filtration process. Bottled water is not automatically a safer alternative: it can contain contaminants from plastic or the source itself and is not subject to the same frequencies of control as public network water. The information contained in this article is intended for general informative and scientific purposes. It does not substitute for the advice of a doctor or healthcare professional. In case of doubt about the quality of consumed water or a particular exposure risk, it is recommended to consult local health authorities (ARS) or a healthcare professional.