by This story is part of a series, “Fighting Chemicals Forever’: Women face pervasive PFAS risks.”
Although “forever chemicals” have been linked to many adverse health effects from cancer to kidney disease, they may have different effects on male and female bodies.
“Often you see something in one sex and not the other,” said Linda Birnbaum, former head of the National Institute of Environmental Health Sciences and the National Toxicology Program.
“Forever chemicals,” or PFAS, are found in many common household products and in certain types of firefighting foam. Their use in manufacturing is the result of their proliferation in the air, water and soil, and they are estimated to be in the blood of about 97 percent of Americans. The federal government recently set the first national limits on some types of these substances in drinking water.
Some of the different ways in which pervasive chemicals affect men and women are clearly connected to reproductive organs.
PFAS exposure is associated with an increased risk of testicular cancer, for example: A panel of scientists established in 2012 that there is a “probable link” between exposure to a type of PFAS called PFOA and testicular cancer.
A toxicology review in January 2022 explored a number of issues related to the female reproductive system – such as birth defects, fertility and changes in the menstrual cycle – that could be linked to PFAS exposure. “The effects are multiple,” the authors found, although they said it’s not yet clear exactly how the substances target the female endocrine and reproductive systems because of a “large research gap.”
A study published in September attempted to narrow that gap by zooming in on sex-specific relationships between three classes of potential endocrine disruptors — including PFAS — and previous diagnoses of hormone-related cancers. The scientists noted striking indications of these differences in melanoma: Higher blood levels of PFAS were linked to earlier diagnoses in women, but not in men.
“Sex-specific associations between PFAS chemicals and previous melanoma diagnosis suggest that sex-mediated mechanisms may be at play,” wrote the authors, from the University of Southern California and the University of Michigan.
Although the exact mechanism behind the melanoma link is still uncertain, scientists have speculated that because these tumor cells have estrogen receptors, environmental contaminants that mimic estrogenic activity – such as PFAS – may be contributing to the growth of cancer among women.
Like melanoma, other health effects that are less clearly linked to sex-specific characteristics may still affect men and women after exposure to environmental contaminants, such as PFAS.
High blood pressure, for example, seems to be more pronounced in women than in men, recent studies have shown.
Sometimes, this manifests in hypertension that occurs during pregnancy, which can lead to a potentially fatal condition called preeclampsia—a possible effect of PFAS exposure, said researcher Erin P. Hines. in the Environmental Protection Agency’s reproductive toxicology division, is eager to see more. research on.
“Having preeclampsia or pregnancy-induced hypertension during pregnancy can change a woman’s health outcome for the rest of her life, putting her at greater risk for adverse cardiovascular outcomes such as stroke,” said Hines, at note that this risk is independent of PFAS exposure.
“But if you have a pregnancy with preeclampsia or one of these hypertensive disorders of pregnancy, during your lifetime, there are increased risks of morbidity and mortality. [with] cardiovascular events,” she said.
Beyond the type that would occur with pregnancy, additional research has also identified hypertension in the female population exposed to PFAS in general.
A 2022 study from the American Heart Association found that middle-aged women had a greater risk of hypertension with higher blood levels of certain types of PFAS. Analyzing the annual follow-up visits of 1,058 middle-aged women who were initially free of hypertension from 1999 to 2017, the scientists found that 470 people developed this condition. The authors found that women aged 45-56 with high concentrations of PFOS in their blood had a 42 percent higher chance of developing high blood pressure, and those with high concentrations of PFOA had a 47 percent higher chance. Women with high concentrations of the seven types of PFAS examined by the study had a 71 percent increased risk of developing high blood pressure.
Study author Ning Ding said PFAS exposure also appears to put women at greater risk more broadly.
“Women appear to be particularly vulnerable when exposed to these chemicals,” Ding, a postdoctoral fellow in the University of Michigan’s epidemiology department, said in a statement. “Exposure may be an underappreciated risk factor for cardiovascular disease risk in women.”
Studies are also emerging that suggest links between PFAS and other health outcomes in girls or women, such as ADHD in girls or weight gain in women. Scientists have also linked PFAS exposure to an increased susceptibility to developing diabetes among middle-aged women. Some types of PFAS may interfere with the regulatory behavior of certain protein molecules and, in turn, raise the risk of diabetes within this cohort, according to an April 2022 study.
Although the researchers emphasized that there is a lack of evidence of sex-dependent links between PFAS and diabetes in humans, they pointed to another recent study that showed that the metabolic responses of female mice to PFOA exposure were greater than those of male mice. .
Meanwhile, another effect of PFAS has been shown to mainly affect boys. A 2022 study found that teenage boys exposed to a combination of substances and another type of hormone-disrupting chemical called phthalates may have lower bone density – leading to weaker bones. and more prone to breakage.
Some PFAS-related vulnerabilities may be rooted in utero. Prenatal exposure to the substances has been linked to preterm births, changes in birth weight or congenital issues that emerge later in childhood — including effects on ADHD or IQ, according to Birnbaum.
“We’re seeing with PFAS – like many chemicals that really disrupt hormone systems – you get a boy or girl difference,” she said, noting that some effects are seen in one sex.
“If you look at, say, young boys and girls together, you might not see an effect. But if you separate the sexes, suddenly you can see an effect in one of them,” Birnbaum added.
But she also admitted that not all researchers are happy with that kind of separation: “What’s interesting to me is that there are some people who don’t want to believe that. They think, well, if you don’t see it in both, you know, males and females, it can’t be happening.”
The discovery of sex-dependent health effects often depends on exactly what scientists are looking for in their research, according to Birnbaum.
“It’s kind of like the old saying: If you don’t look, you don’t see. But when you start looking, you start finding.”
For the latest news, weather, sports, and video streaming, go to The Hill.
