Each year in the United States, a little over 6,800 cancers are caused by the presence of PFAS (see box below) in drinking water. This is what a study from the Keck School of Medicine in Los Angeles (United States) reveals, published in the Journal of Exposure Science & Environmental Epidemiology. Thus, according to this work, people exposed to PFAS in their tap water have up to 33% additional risks of developing certain types of cancer.
In this study, scientists looked at regions of the United States where maximum levels of PFAS in public drinking water systems exceeded the recommendations of the United States Environmental Protection Agency (EPA), from 2013 to 2015 and from 2023 to 2024, particularly around New York or Chicago for example. The researchers compared these results with cancer incidence data from 2016 to 2021 from the American program Surveillance, Epidemiology, and End Results.
What are PFAS?
THE PFAS or perfluoroalkyl and polyfluoroalkyl substances (also called " "eternal pollutants") are chemicals used in many industrial processes and products such as frying pans, food containers and tap water. They are very resistant to degradation and can therefore persist for up to several centuries in the environment.
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Up to 33% more risk of developing cancer
Thus, by controlling for external factors such as age, sex, smoking, obesity or the presence of other pollutants, they found that, in regions where PFAS levels in drinking water exceeded the recommendations of 0.004 micrograms per liter (μg/L), depending on the pollutant, residents had an additional risk of developing certain types of cancers of 2 to 33% compared to the rest of the population.
Indeed, cancers of the oral cavity, pharynx, lungs, digestive system, brain, urinary system and thyroid are associated here with the presence of PFAS. in large quantities, ranging from 0.002 to 0.020 micrograms per liter (μg/L) of PFAS in the public drinking water system.
Illustration of the distribution of PFAS in drinking water and the average annual incidence of cancer between 2016 and 2021. Credits: Journal of Exposure Science & Environmental Epidemiology
Furthermore, according to a study by theUnited States Geological Survey published in 2023, approximately 45% of U.S. drinking water contains at least one “ eternal pollutant ». That is to say that nearly half of Americans would be contaminated with PFAS through their tap water. In addition to other exposures to these pollutants, on food packaging, non-stick utensils or even via certain cosmetic products, PFAS are present almost everywhere in the country. Significantly increasing health risks, including developing cancers.
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Increased monitoring of PFAS is needed
This study provides new evidence in the battle against the use of PFAS and the need to increase monitoring of these products, which are as harmful to the environment as they are to humans. Thus, by 2029, theEPA should monitor levels of six different PFAS in drinking water in the United States to prevent people from becoming overly contaminated.
What does the law say in France?
In France, in order to respect the European limits set for 2026, the presence of 20 PFAS in water intended for human consumption has been regulated since January 2023 and limited to 0.1 micrograms per liter (μg/L) for tap water and 0.2 micrograms per liter (μg/L) for water before treatment according to the Ministry of Health.
According to researcher Shiwen Li, author of the study, "These results allow us to draw an initial conclusion on the link between certain rare cancers and PFAS", thus encouraging "to search for each of these links in a more individualized and more precise manner", in order to understand how the “eternal pollutants” impact the body and lead to the development of cancer. Indeed, "Some PFAS, which have been less studied, need to be more closely monitored, and others, which may not yet be strictly regulated, need to be," according to the researcher.