Male fetuses, bathed in forever chemicals, have lower sperm counts as adults: study

It is an industrial irony that nonstick pans, marketed as impervious to any compound that may linger on them, are themselves producing chemicals that stick around forever in the bloodstreams of animals. 

Formally, these substances are known as PFAS, or per- and polyfluoroalkyl substances; and they are known as forever chemicals because, under normal environmental conditions, they never break down. Try as you might, it is near-impossible to escape them because PFAS are used in hundreds of commonly-used products. They are linked to health conditions from high-blood pressure to liver disease, and have raised enough public alarm that last year Congress began to take small steps toward addressing the problem.

And every day we learn more about the extent of health issues that can be caused by these exotic substances. Indeed, in a recent study in the peer-reviewed journal Environmental Health Perspectives, scientists have linked PFAS to lowered sperm quality.

Incredibly, the process that causes this begins in utero, with a biologically male fetus. As the unborn child is drenched in the countless chemicals ingested by its parent, its developing body changes in unnatural and sometimes unhealthy ways. In their recent study, the scientists behind the Environmental Health Perspectives article found that a mixture of seven common PFAS — at least, for pregnant mothers exposed to them during the first trimesters of their pregnancy — were linked to their biologically male children having "lower sperm concentration, lower total sperm count, and higher proportions of nonprogressive and immotile sperm in young adulthood." This means that their biologically male offspring of mothers exposed to these PFAS produced less sperm and, when they did produce sperm, often created sperm that did not move forward or were in other ways deformed.

The suggestion is indeed alarming, though researchers were quick to note that this study is not the final word on the matter.

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"The study is an association study, and cannot say anything about causality," Dr. Sandra Søgaard Tøttenborg of the University of Copenhagen and lead author of the article told Salon by email. Its significance is that it is the first scientific study to examine PFAS exposure during the early stages in pregnancy, which is when male genitalia are developed. In addition, it is the first study to look at mixtures of PFAS.

"Earlier studies of PFAS exposure later in pregnancy have focused on single substances, which is an unrealistic scenario considering that chemicals are embedded into virtually every aspect of our modern lives," Tøttenborg explained. "The study showed a statistically significant association between exposure to a mixture of PFAS in early pregnancy and lower sperm concentration and total sperm count and higher proportion of non-progressive and immotile sperm."

Although the study was conducted in Denmark, PFAS are also ubiquitous in the United States. As of June 2022, all 50 states as well as two territories have PFAS contamination in at least 2,858 known locations. Despite this problem, only seven states have passed PFAS limits in their drinking water including Maine, Massachusetts, Michigan, New Hampshire, New Jersey, New York and Vermont. This alone is unlikely to make a dent in the problem of individual exposure — if, indeed, any regulations are capable of doing so.

"For individuals it can be very hard to limit our exposure to PFAS, since they are used in so many products and manufacturers don't always disclose their use," Dr. Elizabeth Costello, a PhD student at the University of Southern California who has done other PFAS research but who was not involved in the recent study, told Salon by email. She had earlier observed that these exposures can occur when humans drink water or eat food that has touched contaminated packaging. "PFAS can also be detected in many water sources, including rainwater, throughout the world. However, we're starting to see more action on PFAS at the state level: California just committed to removing PFAS from fabrics and cosmetics in the next few years."

In terms of the specific implications of the new study, Tøttenborg cautioned against conflating poor semen quality with infertility as a whole.

"Poor semen quality is a common issue for couples struggling to conceive, but you can have normal semen quality and still be infertile and vice versa," Tøttenborg explained. "Harmful effects on the male reproductive system after exposure to PFAS is shown in a series of animal experiments. In human epidemiological studies at environmentally relevant exposure levels, the findings have been less clear."

Again, however, the new study breaks ground because while "previous risk assessments have widely focused on single substance exposure to a few legacy PFAS," this new one acknowledges that "exposure to chemicals rarely occur in isolation."