Researchers from the Keck School of Medicine de
“Data-Gt-translate-attrattes =” ({“attribute =” “tabindex =” 0 “role =” link “> USC discovered a link between the levels of “permanent chemicals” of human origin in drinking water and an increased risk of certain cancers, in particular those affecting the digestive system, the endocrine system, the respiratory system, as well as the mouth and The throat.
A new search for the USC Keck School of Medicine reveals that communities whose drinking water is contaminated by manufactured chemicals called per- and polyfluoroalkyle substances (PFAS) are faced with a 33 % higher risk of developing certain Cancers.
Published in the Exhibition science journal and environmental epidemiology and funded by the
“Data-gt-translate-attributes =” ({“attribute =” “tabindex =” 0 “role =” link “> National Institutes ofThis is the first American study to examine directly the link between PFAS contamination in drinking water and cancer.
PFAS is widely used in consumer products such as food and food packaging and have been detected in around 45 % of drinking water supplies in the United States. These chemicals slowly degrade and accumulate in the body over time. Previous studies have established a link between exposure to PFAS and several health problems, including kidney, breast and testicles.
To draw up a more complete table of PFAS and the risk of cancer, researchers from the Keck School of Medicine conducted an ecological study, which uses large sets of data at the level of the population to identify exposure models and risks Associates. They discovered that between 2016 and 2021, the counties of the United States where drinking water was contaminated by the PFAS had a higher impact of certain types of cancer, which diffraged by sex. Overall, it is estimated that the pfas present in drinking water contribute to more than 6,800 cases of cancer each year, on the basis of the most recent data of the American environmental protection agency (EPA) .
“These results allow us to draw a first conclusion on the link between certain rare cancers and the PFAS,” said Shiwen (Sherlock) Li, PHD, postdoctoral researcher in the Department of Population and Public Health of Keck School of Medicine and first author of the study. “This suggests that it is worth studying each of these links in a more individualized and more precise manner.”
In addition to providing a roadmap to researchers, the results highlight the importance of regulating PFAS. From 2029, the EPA will control the levels of six types of PFAS in drinking water, but more strict limits could ultimately be necessary to protect public health, said LI.
The balance sheet of the PFAS
To understand the link between PFAS contamination and the incidence of cancer, the researchers compared two exhaustive data sets: one covering all cases of cancer reported and the other including all the data on the PFAS in the ‘Drinking water across the country. Data on cancer cases between 2016 and 2021 were obtained from the surveillance, epidemiology and final results program of the National Cancer Institute, while data on PFAS levels in public drinking water (2013- 2024) came from the programs for the surveillance rules for non -regulated EPA contaminants.
Li and his colleagues have checked a number of factors likely to influence the risk of cancer. At the individual level, these criteria included age and sex; At the county level, they excluded changes in the incidence of cancer due to socio-economic status, smoking rates, prevalence of obesity, urbanity (how urban or rural areas are ) and to the presence of other pollutants.
The researchers then compared the incidence of cancer in each county to contamination by PFAS in drinking water, using the thresholds recommended by EPA for each type of PFAS. The counties where drinking water exceeded the recommended maximum levels of PFAS had a higher impact of digestive, endocrine, respiratory and mouth and throat cancer. Incidence increases varied from slightly high to 2 % to 33 % considerably (the increased incidence of mouth and throat cancers linked to perfluorobutaneulfonic
“Data-gt-translate-attributes =” ({“attribute =” “tabindex =” 0 “role =” link “> acidor pfbs).
Men living in counties where drinking water was contaminated had a higher impact of leukemia, as well as cancers of the urinary system, brain and soft tissues, compared to men living in areas where water was not contaminated. Women presented a higher impact of thyroid, mouth, throat and soft tissue cancer. Based on the latest EPA data, researchers believe that contamination of drinking water by PFAS contributes to 6,864 cases of cancer per year.
“When people hear that PFASs are associated with cancer, it is difficult to know how it is relevant. By calculating the number of cases of attributable cancer, we are able to estimate how many people may be affected, “said Li, in particular by deducting the personal and financial report of these cases year after year.
Protect public health
These results at the population level reveal associations between PFAS and rare cancers that could go unnoticed. Then, individual studies are necessary to determine whether the link is causal and explore the biological mechanisms involved.
On the regulations side, the results are added to the growing evidence that PFAS levels should be limited and suggest that the proposed changes may not go far enough.
“Some PFASs that have been less studied must be monitored more, and regulators must think about other PFASs that may not yet be strictly regulated,” said Li.
Reference: “Associations between per- and polyfluoroalkylated substances (PFAS) and the incidence of cancer at the counties between 2016 and 2021 and the burden of incident cancer attributable to PFAS in drinking water in the United States” by Shiwen Li , Paulina Oliva, Lu Zhang, Jesse a Goodrich, Rob McConnell, David V. Conti, Lida Chatzi and Max Aung, January 9, 2025, Exhibition science journal and environmental epidemiology.
DOI: 10.1038/S41370-024-00742-2
Work is part of a collaboration between the Southern California Environmental Health Sciences Center, funded by the National Institute of Environmental Health Sciences, and the USC Norris Understanding Cancer Center of the Keck School of Medicine.
This work was supported by a pilot subsidy of Southern California Environmental Health Sciences Center (P30ES007048) and the National Cancer Institute (5p30ca014089-47).
