With all of the depressing news in the world, many people are justifiably afraid that humanity is careening toward extinction. A 2021 poll of 10,000 young people aged 16 to 25 found that 56% believed humanity is "doomed" due to climate change. Even if climate change doesn't take us out, there are the existential threats posed by war with nuclear explosives or other weapons of mass destruction, a lurking specter thanks to global conflicts spanning from Israel to Ukraine.
These are depressing subjects to contemplate, but few are more relevant — and by discussing them, we at least make it theoretically possible to solve the underlying problems.
But what if it is humanity's steep decline came not from the usual suspects, like climate change or apocalyptic AI, but by something more basic? What if our patriarchal society is brought to its knees by universal impotence?
That may be where exactly we are headed. According to numerous metrics, humanity is in the midst of a fertility crisis. In April, the World Health Organization released a report revealing that roughly 1 in 6 people attempting to conceive today experience fertility issues. In the United States roughly 9% of men and 11% of women have fertility issues, according to the United States National Institutes of Health.
Yet with current technology, it's unlikely that humanity will go extinct from this alone. Instead, I believe our species faces a future in which only the rich will be able to reproduce.
That statement may seem overly dramatic, but the evidence seems to be taking us down this path. As environmental and reproductive epidemiologist Dr. Shanna Swan reported in her 2021 book "Count Down: How Our Modern World Is Threatening Sperm Counts, Altering Male and Female Reproductive Development, and Imperiling the Future of the Human Race," the average human sperm count has roughly halved, plummeting from 99 million per milliliter to 47 million per milliliter between 1973 and 2011. Swan is not alone in reaching this conclusion. Hagai Levine, professor of epidemiology at the Hebrew University of Jerusalem, found that sperm counts fell an average of 1.2% every year between 1973 to 2018, from 104 to 49 million/ml. As of 2000, the rate of decline increased to more than 2.6% for every year.
What's causing this trend? It's most likely environmental pollution, especially endocrine disruptors, or chemicals that can interfere with the proper functioning of our hormones.
In her book, Swan focused on the endocrine disruptors widely used in plastics. There is no realistic way that we will ever remove all of these endocrine disruptors from our environment, at least not any time soon. If this downward trend in fertility continues, and once our average sperm count reaches less than 15 million per milliliter, the only people able to reproduce will be those who can afford expensive medical technology like in vitro fertilization (IVF), which makes it possible to do so. (Levine places the threshold sperm count number at 40 million per milliliter.)
In her book — which I consider a must read for anyone who wants to understand humanity's (likely) impending extinction — Dr. Swan examined phthalates, bisphenols and other plastic pollutants. As Swan told Salon in 2021, if these chemicals interfere with male fetal development at the "delicately programmed time" during which they develop their reproductive system, the eventual adult will suffer with issues like inadequate sperm count. Plastic items containing these chemicals are literally everywhere: From medical tubing and automobile parts to beverage containers and vinyl flooring, from the packaging containing our products to the fish we eat from the ocean (thanks, microplastics).
Women are not spared from endocrine disruptors either. An August study in the journal Frontiers in Physiology found that microplastics and nanoplastics seem to have a harmful effect on the reproductive systems of females in multiple other species, not just humans, though the authors cautioned it was too early to make firm conclusions.
But chemicals from plastics are not alone in disrupting our endocrine system. They are only one ingredient in a toxic stew that is literally hitting us in our collective gonads. According to a recent study in the journal Environmental Health Perspectives, common chemicals in pesticides like organophosphates and N-methyl carbamates are linked to plummeting sperm counts. Just as Swan reached her conclusion after analyzing decades of research on global sperm counts and plastics-based endocrine disruptors, the authors of the study compared sperm counts of men who work in agriculture (and are thus more exposed to pesticides) with the sperm of men with less exposure. Yet no man is totally unexposed to these chemicals; they are ubiquitous in the pesticides which cover any food we grow from the ground. (Pesticides have also been linked to fertility issues in women as well as ovarian disorders, stillbirths, premature births and development abnormalities.)
Humanity's fertility is similarly screwed, so to speak, because of so-called "forever chemicals," or per- and polyfluoroalkyl substances (PFAS). A 2022 study in the journal Environmental Health Perspectives found that mothers exposed to a mixture of seven common PFAS produced male offspring who had less sperm and/or unhealthy sperm. Speaking with Salon by email at the time, lead author Dr. Sandra Søgaard Tøttenborg of the University of Copenhagen emphasized that the study had only proved a link, not causation. Even so, it determined that there is "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."
A group of researchers from Mount Sinai Hospital found PFAS also have a detrimental impact on female fertility, as detailed in a paper in the journal Science of the Total Environment.
“PFAS can disrupt our reproductive hormones and have been linked with delayed puberty onset and increased risks for endometriosis and polycystic ovary syndrome in few previous studies. What our study adds is that PFAS may also decrease fertility in women who are generally healthy and are naturally trying to conceive,” senior author Damaskini Valvi, an assistant professor of environmental medicine and public health at Icahn Mount Sinai and a nationally recognized expert on the dangers of PFAS, said in a statement. “We also know that PFAS exposure begins in utero and transfers from the mother to the fetus, as many PFAS have been detected in cord blood, the placenta, and breast milk. Preventing exposure to PFAS is therefore essential to protect women’s health as well as the health of their children.”
Like pesticides and plastics, there is simply no getting away from PFAS. They are in fast food wrappers and receipt paper, non-stick cookware and water-resistant fabrics, microwave popcorn bags and cosmetics. So what can humanity do to address this impending sperm count crisis?
Ideally, we would completely stop using products that contain endocrine disruptors. This means radically overhauling how we grow our food and manufacture consumer products, a self-imposed economic revolution that requires more concerted willpower than our species has demonstrated up to this point. Therefore the only alternative is to make it possible for us to reproduce even with sperm count lower than 15 million per milliliter. The good news is that we have the technology to make that possible through IVF. The bad news is that the technology is not provided universally, much in the way that education and health care are largely inaccessible in the United States.
That is why I hope to start the conversation now by saying that if IVF and other assisted reproductive technologies are not universally accessible, then only the rich will be able to breed in the future. It is a future we can avoid, but it has to start with an honest conversation about the technology we use today.
An earlier version of this article originally appeared in Salon's Lab Notes, a weekly newsletter from our Science & Health team.
