So-called forever chemicals have been detected in just about everything, from tap water to car seats. But research has found that these per- and polyfluoroalkyl substances, or PFAS, have also been linked to several serious health conditions, including obesity, infertility, lowered immune function and high blood pressure.
Now, new government-funded research has found even more potential health concerns to add to the list: Forever chemicals may raise the risk of developing ovarian cancer, melanoma and other types of cancer in women.
Rates of ovarian cancer have been steadily dropping in the U.S., while melanoma cases have been increasing. But what's behind the link between forever chemicals and cancer, and how can you lower your risk? Experts explain.
What the study says
The new study, which was published in the Journal of Exposure Science & Environmental Epidemiology, found that women previously diagnosed with ovarian cancer, melanoma and other types of cancer are also more likely to have been exposed to several forever chemicals.
What are the key findings?
For the study, researchers analyzed a sample of more than 10,000 adults who participated in the National Health and Nutrition Examination Survey between 2005 and 2018. The researchers analyzed the medical records of study participants, as well as concentrations of PFAS and phenols (compounds often used as antiseptics and disinfectants) in their blood.
What they discovered: Women who had a previous diagnosis of melanoma, ovarian cancer or uterine cancer had higher concentrations of forever chemicals and phenols in their blood than people without these diagnoses.
Overall, the data found that women with higher exposure to the forever chemical perfluorodecanoic acid (PFDE) had twice the odds of being diagnosed with melanoma, while women exposed to perfluorononanoic acid (PFNA) and perfluoroundecanoic acid (PFUA) had nearly double the odds of a previous melanoma diagnosis. Women who had been diagnosed with uterine cancer were more likely to have higher levels of PFNA.
Forever chemicals aren't rare: One report from the Centers for Disease Control and Prevention found PFAS in the blood of 97% of Americans. Research published in August from the U.S. Geological Survey found that 45% of American tap water is contaminated with forever chemicals.
What experts think
There's a lot that's still being explored about the impact of forever chemicals on health, study co-author Max Aung, assistant professor in the division of environmental health at the University of Southern California, Keck School of Medicine, tells Yahoo Life. "There is widespread human exposure to PFAS and phenol chemicals, and therefore we need to know the health risks of human exposure to these chemicals," he says.
While research into this area is ongoing, Aung points out that "increasing animal and in vitro studies indicate that PFAS can interfere with hormone function, immune system, liver function and metabolism." All of those may influence a person's cancer risk, he says.
But people shouldn't be "overly alarmed" by the results of one study, Dr. Robert Wenham, chair of Moffitt Cancer Center’s department of gynecologic oncology, tells Yahoo Life. While the study found links between higher blood levels of PFAS and the odds of having had cancer in the past, it didn't find that forever chemicals actually cause these cancers, Wenham says. Instead, it helps give researchers something to analyze more in future studies to see if there is a cause and effect.
"Further, the degree of effect may be moderate when compared to other known risks of some of these cancers," Wenham says. He cites this example: The odds of developing endometrial cancer with higher levels of PFAS exposure is 1.55, but in someone who has obesity, the odds are almost 40 times that.
As for why forever chemicals may raise the risk of developing certain cancers, Wenham says that PFAS may affect hormone levels or interact with DNA and cause errors and mutations that can lead to cancer — but it's not totally clear at this point.
Why it matters
Again, PFAS exposure is common, and it can be difficult to avoid these forever chemicals. Wenham says there is "potentially some" impact that PFAS may have on cancer risk, adding, "It makes sense to decrease our risks as much as is reasonable."
That means avoiding certain products, such as nonstick cookware and food packaging containers, as much as possible, Aung says. "There are also some water filters that can help reduce PFAS contamination in drinking water," he notes, pointing to a guide from the Environmental Working Group as a good source.
But Wenham says there are other things you can do to lower your risk of developing these cancers — and they may have a bigger impact than trying to reduce your PFAS exposure.
"You would do much better to be mindful of the many other risks for these cancers in one's control that are already understood and that make a bigger impact," he says. To prevent melanoma, for example, you can minimize your sun exposure, wear sunscreen when you do need to be out in the sun, strive to maintain a healthy weight and avoid smoking, he says.
The latest study didn't find that these PFAS cause certain types of cancer, but it did establish a link — and that's one that experts say should be explored more in the future. "The study findings help prioritize these chemicals as important for future investigations of environmental risk factors for cancer," Aung says.