A recent study examining the long-term presence of per- and polyfluoroalkyl substances (PFAS) in human blood following long-term exposure to the chemicals after a paper mill was linked to local drinking water contamination found that women in the low-exposure study group were more successful at eliminating the PFAS from their bodies than men in the same group.
“It is thought to be related to a difference in hormones,” the lead author told Newsweek.
Why It Matters
PFAS encompass thousands of man-made chemicals found in everyday items such as nonstick cookware, firefighting foams, grease-resistant food wrappers and water-resistant clothing. PFAS, known as “forever chemicals” because of the long time it takes them to break down, can cause harm in high exposure amounts.
The chemicals can stay in the bloodstream years after intervention has occurred, the study found. However, for those in the low-exposure group, men had a higher chance of retaining the PFAS in their blood long term.
What to Know
Michigan State University researchers conducted the study in southwestern Michigan, where it was discovered the drinking water had been contaminated by PFAS in 2018.
Researchers divided the study participants into a high-exposure group, those who had drunk the city water, and a low-exposure group, those who had drank water from private wells.
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“While sex was not a major predictor of serum levels in our multiple regression models, in a stratified analysis, we observed significantly higher serum geometric means for PFOS and PFHpS for males compared to females in the low exposure group,” the study found. “This is consistent with other studies and may be influenced by elimination via menstruation, childbirth, and breastfeeding.”
Lead study author Courtney Carignan told Newsweek that other studies have found similar results in that there are lower levels of PFAS chemicals in women of childbearing years compared to men.
“It is thought to be related to a difference in hormones,” she said.
There are other reasons women’s bodies are better at removing PFAS than men’s.
“Several of the ways PFAS are excreted are through menstruation, childbirth and breastfeeding,” Carignan said.
However, those methods didn’t make a difference for women in the high-exposure group.
“That difference is overwhelmed by high exposure through drinking water,” she said.
The study also found that more than half of the study participants in the high-exposure group still had PFAS blood levels above the national guidance even years after intervention occurred.
High levels of certain PFAS can cause heightened cholesterol, decreased vaccine response in children, changes in liver enzymes, increased risk of high blood pressure or preeclampsia in pregnant women, decreases in birth weight and an increased risk of kidney or testicular cancer, according to an Agency for Toxic Substances and Disease Registry (ATSDR) webpage dedicated to PFAS.
What People Are Saying
The study said: “Overall, these results highlight the role of drinking water as a predominant source of PFAS exposure for this community and the persistence of elevated concentrations in serum even 3 years after the intervention.”
The Centers for Disease Control and Prevention (CDC) said in a webpage about PFAS: “CDC/ATSDR recognizes that exposure to high levels of PFAS may impact the immune system. A National Toxicology Program review found that exposure to perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) is an immune hazard to humans based on a high level of evidence that PFOA and PFOS suppressed the antibody response from animals and a moderate level of evidence from studies in humans.”
What Happens Next
Carignan said researchers are now examining how elevated exposure to PFAS impacts local and homegrown food after intervention occurred. That study will come out in “the next year or so.”