Infertility is every hopeful parent's worst nightmare. Defined as the inability of an individual to conceive within 12 months of engaging in regular unprotected intercourse, infertility impacts at least 186 million people in the world today. It is also on the rise — a fact that, as a recent study demonstrates, may be linked to the increasing prevalence of a class of chemicals so common, they are definitely in your body right now.
Women with higher blood concentrations of seven specific and ubiquitous PFAS were 30 percent to 40 percent less likely to be able to attain a clinical pregnancy and deliver a live birth.
These so-called "forever chemicals" (so named because they never break down on their own) are known as PFAS, or per- and polyfluoroalkyl substances. PFAS are among the most common commercially used chemicals in the world, appearing in everything from food packaging, popcorn bags, paper wrapping and umbrellas to cooking equipment, waterproof clothing, furniture and carpets. PFAS have also been linked to a number of health ailments, albeit through correlation (more on that in a moment): Scientists have found connections between PFAS and high blood pressure, liver disease and low sperm count. Now you can add problems with conceiving to that list.
Indeed, according to a new paper in the journal Science of the Total Environment, women with higher blood concentrations of seven specific and ubiquitous PFAS were 30 percent to 40 percent less likely to be able to attain a clinical pregnancy and deliver a live birth. This was based on an analysis of 382 women in Singapore of reproductive age who were trying to conceive. The study monitored their progress over a 12-month span.
At least one of these PFAS, perfluorodecanoic acid (PFDA), has already been individually linked to infertility. PFDA is an extremely common breakdown product of stain-and grease-proof coatings on food packaging, including popcorn bags as well as some fast food wrappers and containers. Yet the scientists behind this study, who spoke to Salon, were very clear about one thing: Women trying to conceive of a child should stay away from all of these PFAS to the greatest extent that they can.
Women who are trying to conceive "should definitely be sure to avoid foods that have been associated with increased PFAS concentrations in previous studies," Dr. Nathan Cohen, lead author of the study and a researcher at the Icahn School of Medicine at Mount Sinai, told Salon by email. "These include foods that are often packaged in materials that contain PFAS, such as fast food, popcorn, and pizza. Fried foods, such as fried fish, should also be avoided."
Co-author Dr. Damaskini Valvi, who is also from the Icahn School of Medicine, suggested that concerned would-be parents should use certified water filters to remove PFAS that leech into the water supply. They can also avoid foods from containers that contain a lot of PFAS (such as pizza boxes or soda cups), as well as prepare their meals with stainless pans instead of non-stick cookware. The latter are covered in substances like PTFE, better known as teflon.
"Avoid in general stain-resistant and water-resistant products, because studies have shown that these products contain multiple PFAS," Valvi added. At the same time, the scientist ruefully pointed out that "because there are thousands of PFAS and we now [face] a global contamination problem, we cannot avoid PFAS exposure completely on our own. It is also critical to advocate for strict regulations that ban the use of PFAS."
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"Regulating each chemical individually means we will constantly be playing catch up."
When asked what other kinds of policies could be effective, Valvi called for stopping the production of all new PFAS and regulating those that still exist. She noted that there are more than 10,000 PFAS extant in the environment today, but in the United States only a few PFAS are regulated, "not enough to protect public health."
Liz Costello — a PhD student at the University of Southern California who was involved in a recent study linking PFAS to liver disease, but was not involved in the latest paper — echoed Valvi's point. Costello noted that "regulating each chemical individually means we will constantly be playing catch up; as this study shows, PFAS mixtures as well as newer 'replacements' are also associated with adverse health effects, and PFAS should ideally be regulated as a class." Costello also called for strict standards on acceptable PFAS levels in drinking water, soil and other natural sources where people might be exposed to them.
The individual PFAS in this study have faced controversy before. In addition to PDFA, the study isolated as unsafe chemicals like perfluorooctanesulfonic acid (PFOS), linear perfluorooctanoic acid (PFOA), perfluoroheptanoic acid (PFHpA), perfluorohexanesulfonic acid (PFHxS), perfluorononanoic acid (PFNA), and perfluoroheptanesulfonic acid (PFHpS). Many of these PFAS (specifically PFOS, PFOA, and PFHxS) had been previously identified as potentially hazardous in a June study, which linked them to hypertension. Studies like the latest one on pregnancy build on the circumstantial case which exists about the risk posed by this class of chemicals. Yet inconveniently for those who have been likely harmed by exposure, it is practically impossible to definitively prove that PFAS are the cause of these medical maladies.
"The more studies that point in the same direction, the more sure we are."
"Since we for ethical reasons cannot study the health effects of PFAS in randomized clinical trials, well-executed epidemiological studies like this one are important for our understanding of the substance group," writes Dr. Sandra Søgaard Tøttenborg of the University of Copenhagen. Tøttenborg led a study published in October that linked prenatal PFAS exposure to lower sperm counts; like Costello, Tøttenborg was also not involved in the latest study. "And the more studies that point in the same direction, the more sure we are," Tøttenborg continued. She also praised the study for focusing on mixtures of PFAS rather than individual chemicals, "as humans are exposed to hundreds of chemicals simultaneously on an everyday basis. This is a more realistic scenario than examining them one by one."
PFAS are not the only common industrial contaminant in the food chain that may cause infertility. As Valvi observed, there is also research linking plasticizers like phthalates and bisphenols to drops in sperm count. Indeed, as Mount Sinai environmental health expert Dr. Shanna Swan told Salon in 2021, if sperm counts continue to decline at their current rate — which, given their likely link to plastic pollution, will almost certainly happen unless drastic steps are taken — humanity could face an infertility crisis in mere decades.
"We continuously see that other chemicals can also affect fertility," including PFAS, Valvi explained. "It's a problem that we need to address, since infertility rates are on [the] rise globally and every day more couples require fertility treatments."
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