‘Forever chemicals’ are known to linger in the body. Menstruation helps to expel them

This story is part of a series, “Fighting ‘Chemicals Forever’: Women Face Widespread PFAS Risks.”

The “forever chemicals” linked to cancer got their nickname because of how long they remain without breaking down – in the environment and in the human body. However, women seem to have a way to get rid of at least some of the compounds.

“Some PFAS bind tightly to blood proteins, and when women menstruate, they lose the blood proteins bound to PFAS,” Suzanne Fenton, who at the time was a group leader in the Mechanistic Toxicology Branch of the National Institutes of Toxicology Program Nationals. of Health, he told The Hill.

“So this is a unique elimination pathway,” added Fenton, who is now director of the Center for Human Health and the Environment at North Carolina State University.

Forever chemicals or PFAS, which stands for per- and polyfluoroalkyl substances, are a group of toxic compounds that have been linked to several types of cancer and other diseases. They are found in many common household items—including waterproof clothing, nonstick cookware, and cosmetics—and have become widespread in the air, soil, and water due to their use in manufacturing and in certain firefighting foams.

The vast majority of Americans have at least some PFAS in their bloodstream. A widely cited to study published in 2015 by the Centers for Disease Control and Prevention found that 97% of Americans have these substances in their blood.

PFAS tend to bind to proteins like albumin in the blood, according to Erin P. Hines, a researcher in the Environmental Protection Agency’s division of reproductive toxicology. But with menstruation and childbirth, she explained, comes blood loss. Thanks to their monthly cycle, menstruating adults “typically have a lower body burden” or lower blood concentration of PFAS than their non-menstruating peers who live in the same type of community and have a similar socioeconomic status, Hines noted.

One 2022 epidemiological review Several studies on the subject have also stated that “associations between heavy menstrual bleeding and lower PFAS concentrations have been observed.”

Marianthi-Anna Kioumourtzoglou, one of the review’s authors, said the findings show that, at least in theory, some people should be able to “reduce their total body PFAS burden to once a month just by menstruating.”

A January 2022 Toxicology Review published by Fenton’s research team notes that “menstruation appears to be a crucial route of elimination of many PFAS” and potentially explains up to 30 percent of the discrepancy between male and female PFAS blood levels.

“Since 90-99 percent of PFAS in blood are bound to serum albumin, menstrual bleeding may be an important route of elimination for these persistent substances,” the authors stated.

The authors also cited previous search indicating that blood concentrations of PFAS decreased in women who had recently menstruated, relative to individuals who had not experienced such bleeding. Yet another study showed how women who had already gone through menopause – the stage in life when menstrual periods stop – had elevated blood levels of four different types of PFAS, compared to those who had not yet entered this stage.

However, Fenton emphasized that “because some PFAS accumulate in tissues, this pathway is unlikely to rid the body of PFAS.”

The impacts of this potential elimination pathway may also be limited because people are “consistently and constantly exposed” to PFAS, according to Kioumourtzoglou, assistant professor of environmental health sciences at Columbia University.

The effectiveness of menstruation in eliminating PFAS is also restricted when menstruation stops, perhaps as a result of menopause or the use of certain hormonal contraceptives.

“I think it would be safe to say that a woman who uses an oral contraceptive or an IUD and is not menstruating would potentially have a higher concentration of PFAS because she is not menstruating and getting rid of that volume of blood and protein each month,” Hines said.

“Similarly, if you donate blood regularly, you can get rid of some of the body burden caused by environmental chemicals like PFAS,” she added.

​Kioumourtzoglou noted that it is important to gain a greater understanding of this issue because it could inform health care decisions made by doctors and patients.

“Once we understand these dynamics, if this is an important excretion pathway, then perhaps… for some people, we could recommend discontinuing birth control,” she said. “This could potentially be a recommendation for a certain subset of the population who are heavily exposed to PFAS and at the same time do not have an absolute need for birth control, or perhaps they could look at different forms of birth control that do not necessarily reduce the blood. flow.”

But the ability to eliminate some PFAS through menstruation can be a curse as well as a blessing — at least when it comes to scientists’ efforts to understand the dangers of PFAS. Kioumourtzoglou’s review notes that because the substances are excreted in this way, scientists may end up underestimating how much PFAS people with heavy menstrual bleeding are actually exposed to.

“Information about menstrual bleeding may be critical to address measurement errors and avoid underestimating the health impact of PFAS,” the review states.