“Look around. They are in almost everything you see, and in many of the things you don’t see as well,” says Niels Jørgensen, an endocrinologist at Copenhagen’s Rigshospitalet and a leading researcher in male infertility.

The invisible substances he is referring to are ‘endocrine-disrupting chemicals’ (EDCs), which are effectively embedded in the material foundations of modern life. Whether it’s through phthalates used in food wrapping or personal care products, pesticides that leach into soil and groundwater, fabrics treated with flame retardants, cosmetics, lotions, or soaps, most of us are exposed to EDCs on a daily and almost constant basis.

EDCs are of special interest to Jørgensen and others working in the field of infertility research as they have a particularly sinister effect on our ability to reproduce. EDCs can interfere with hormonal systems in various ways, disrupting the ability of both males and females to have children. Their impact on male fertility specifically has garnered increased attention in recent years, due in part to a handful of eye-opening studies showing an accelerating worldwide decline in sperm count – a trend to which the chemicals are a significant contributor.

One oft-cited study, co-authored by Jørgensen and titled “Temporal trends in sperm count: a systematic review and meta-regression analysis”, found that between 1973 and 2011, sperm counts decreased by a staggering 52% for men in North America, Europe, and New Zealand. Later research has supported the results and added that male infertility due to low sperm count also impacts populations in Asia, Africa, Central America, and South America. The contributing factors are many and include poor diet, stress, drinking, smoking, and sedentary lifestyles. But what makes the effect of EDCs especially insidious is that their damage to the male reproductive system begins before birth and can result in genital deformities that permanently inhibit male fertility. EDC exposure later in life can be decreased – in theory at least – but once that initial damage is done, there’s no fixing it.

“Already after six or seven weeks, the male body starts producing hormones that help mature the testicles. If this process is disturbed by the presence of EDCs in the mother for instance, the child’s potential semen quality is lowered already at an early stage,” Jørgensen says, adding that the consensus in the field of fertility research is that EDCs are the most important factor negatively impacting the potential semen quality already in the prenatal development.

The global sperm count decline, due to both EDC exposure and lifestyle factors, has provoked fears of an impending ‘spermpocalypse’ – a future where reproduction without technical assistance becomes all but impossible. Although such anxious premonitions have little empirical basis, the science paints a bleak enough picture.

Some of the problematic EDCs are difficult to pin down, Jørgensen explains, partly because the individual chemicals themselves may not be harmful. When combined in certain ways, however, they achieve a cocktail effect where their so-called ‘anti-androgen effects’ start showing, leading to alterations in reproductive physiology. That’s the assumption at least. So far, the anti-androgen effects of compounds of EDCs have been demonstrated in rodents like rats and mice, though not yet in humans.

That’s not to say scientists aren’t all but sure of their negative effects on us. A recent study has shed new light on the harmful effects of one particularly infamous EDC, the once widely-used insecticide DDT, on human biology. The study, which was published in the journal Environment Health Perspectives, examined two populations of Indigenous men at opposite ends of the globe whose reproductive systems are shown to be impacted by exposure to the chemical. In South Africa, the indigenous Vhavenda men are directly exposed to DDT since the insecticide is still used to combat malaria there. In Greenland, Inuit men absorb the chemical through their diet which relies heavily on large arctic marine animals. In both cases, the research indicated that the sperm of the men is negatively affected to such an extent that that it might even impact subsequent generations.

“This is the first study that unequivocally shows that an exposure to these chemicals changes the sperm epigenome which could be associated with health effects in the next generation, including infertility,” explains co-author of the study Sarah Kimmins, a Professor at the Department of Pathology and Cell Biology, Université de Montréal.

Yet DDT exposure is not exclusive to Greenland and South Africa. Once celebrated as a miracle product, the insecticide was used openhandedly on a global scale to fight insects and tropical diseases before being phased out in much of the world in the 1970s. Its presence in ecosystems still haunts us to this day.

In one recent discovery, scientists found that a large patch of DDT dumped in the ocean off the coast of California in the 1940s and 50s is still resting on the seafloor today, more than half a century later. The DDT patch, larger in size than the city of San Francisco, is the result of half a million barrels of the toxic chemical having been deposited there by producers in Southern California.

It’s a testament both to our reckless relationship with toxic chemicals, as well as to the fact that the great boosts to agricultural yield achieved through technical and chemical innovation in the Green Revolution have come with a hefty environmental bill, to be footed by present and future generations.

“It should be a worldwide concern,” Kimmins says, pointing out how environmental scientists have warned of the risk that DDT exposure is only going to increase as global warming causes the release of the chemicals currently stored in Antarctic glaciers. “If we don’t get in front of this and treat it as a worldwide health crisis, infertility is only going to increase,” she says.

Although severe in scope, DDT contamination of humans and animals is just one example of how our reliance on hormone disrupting chemicals has disquieting consequences. But just how bad can it get? Will our infertility problems continue to increase? Might ‘anti-natalists’ – proponents of voluntary human extinction – eventually get what they want, though in a different way than they imagine?

The bad news is that our dependence on EDCs has rapidly increased in recent decades. Judging from the global production of plastics alone, which have increased from 50 million metric tons in 1976 to more than 400 million metric tons today, we are far from ridding ourselves of the problem. The last 20 years alone have seen a doubling in the production of plastics worldwide, according to data from the OECD, with no signs of slowing down.

Of course, not all plastics contain EDCs, but many do. A report from the Endocrine Society and the International Pollutants Elimination Network found that 144 different chemicals or chemical groups known to be hazardous to human health are actively used in plastics for varying functions. Even bioplastics and biodegradable plastics, often promoted as a safer and more ecological alternative to the conventional kind, can have endocrine- disrupting effects, as they contain similar chemical additives. Testing of human samples, the report states, shows nearly all of us have EDCs in our bodies. And they’re oozing out of us as well; EDCs have been found in semen, saliva, breast milk, urine, blood, and various other bodily fluids.

So, there’s little to suggest that our EDC-related problems will lessen anytime soon, even though growing awareness may bring about change. Infertility, by way of consequence, will be a growing problem as well.

But with the global population continuing its increase during the 21st century, projected to eventually reach 11 billion by 2100, does that have to be such a bad thing? With all the environmental burdens that this population increase brings, why should we care about the effects of chemicals on our ability to reproduce – couldn’t it, in some twisted way, be considered a positive?

Maybe so, if infertility was the only adverse side effect of our reliance on toxic chemicals. In fact, infertility problems can be considered a ‘canary in the coal mine’ of sorts in that they are a biomarker for many other serious health problems. Infertile men are more likely to experience a slew of other hardships, such as higher rates of chronic health disorders and even a shortened lifespan. A recent paper published in Nature and co-authored by Sarah Kimmins points to this fact and urges increased research to map out the connections more fully.

Then, of course, there’s the psychological toll that infertility has on both individuals and couples, as well as the price tag for fertility treatment. The Danish government’s recent announcement of plans to expand free IVF treatment to cover the second child in addition to the first was welcome news for those couples who might be struggling to conceive, but such initiatives are not without their costs. Treatment of this kind, although a blessing to involuntarily childless couples, is combatting the symptoms rather than addressing the root cause of infertility which, according to the WHO, affects one in six people worldwide. There may of course be other pharmacological solutions in the future – medication that can counteract the harmful impacts of EDCs on sperm production. But so far, Jørgensen points out, such ideas haven’t drawn much interest from medicinal companies.

The only real long-term solution to our EDC addiction is also the most difficult one: we will need to greatly reduce our reliance on them. Like the turn away from fossil fuels, doing so directly threatens to undermine many of the conveniences of modern life. It can seem impossible, but it’s necessary, nonetheless.

“I don’t think we will solve the problem simply by phasing out individual EDCs,” Niels Jørgensen says. “We need to decrease the degree of exposure. We need to use fewer chemicals.”

---