Chemicals, the alarm bell of male fertility

In August 2018, a San Francisco jury awarded a former school groundskeeper with terminal cancer $289 million in damages largely attributable to chemical giant Monsanto, maker of the weed killer Roundup, which litigant Dewayne Johnson claimed caused him to suffer from non-Hodgkin’s lymphoma.

The verdict and award served as a gigantic alarm bell to chemical manufacturers. More importantly, it also sounded a clarion call to anyone – which means virtually everyone – coming into contact with everyday chemicals.

Four years before the recent Monsanto verdict, federal researchers decided to try to find out the effects of chemicals on fertility by monitoring 501 couples who were attempting to conceive.

The researchers’ report, published in the May 2014 issue of the journal Fertility and Sterility, included a startling finding: Men were far more likely to experience fertility difficulties as a result of exposure to toxic chemicals.

The difference in the effect between men and women was significantly noticeable in the area of phthalates (pronounced “fth-ah-lees”), substances that make plastics flexible and lotions easier to apply. They can also be found in detergents, packaging, textiles, and common household products.

Here’s where the findings get even more interesting: Because phthalates are present in the kinds of cosmetic products commonly used by women, it would seem that females would have their fertility more significantly impacted. However, the study found that phthalate levels impacted fertility only in men.

Andrea Gore, a professor of pharmacology and toxicology at the University of Texas, told the New York Times, “I wasn’t surprised at all by this finding. We see the cell studies, the animal studies and now the human epidemiology work, and they are all showing us a similar picture.”

That’s because researchers have been focused on the correlation between phthalates and male fertility for over three decades.

A 2003 study indicated a relationship between exposure to phthalates and sperm damage. Six years later, researchers writing in Frontiers of Behavioral Neuroscience wrote that endocrine disruptors – the kind found in phthalates -- were responsible for strange physical alternations in male animal reproductive tracts. Eight years later, a study published in the Journal of Pathology, Microbiology and Immunology found that phthalates negatively impacted the reproductive systems of laboratory rats.

While researchers generally agree that more study is needed to issue conclusive statements about the effects of phthalates on male fertility, many find existing evidence compelling enough to offer ways for men to reduce their exposure.

“These compounds leach from plastics,” Dr. Buck Louis told the NYT. “You can switch to glass for drinking. You can cook your frozen dinners on paper plates.”

(Those concerned about storing and re-heating food in Tupperware containers might take encouragement from a correction to the NYT article which clarified, “Tupperware says its containers are not manufactured with phthalates.”)

But what about the effects of chemicals on items that aren’t so much manufactured as they are grown? Like fruits, vegetables, and other items in the human food chain?

Researchers from the University of Nottingham explored the possible risks of agricultural fertilizer to human fertility – not in the direct sense, as in an agricultural worker coming into contact with a particular fertilizer, which served as the basis for the recent Monsanto case – but in situations where humans have consumed meat from animals grazed on land treated with fertilizer.

The study’s conclusion: “Eating meat from animals grazed on land treated with commonly-used agricultural fertilizers might have serious implications for pregnant women and the future reproductive health of their unborn children”.

For those such as vegetarians and vegans, who might not be concerned about a direct link to eating meat from animals, there’s this to consider: Agricultural fertilizers pose risks to the quality of the soil containing them. This, in turn, could affect the quality of the food that is grown in affected soils.

A February 2016 study focusing on sustainable agriculture found that chemical pesticides and fertilizers did have an impact on soil properties, including the activities of soil enzymes as well as the functional and structural diversity of microbial populations.

Because the affected microbes represent a critical element in soil ecosystems, the researchers warned, “excessive and prolonged usage of chemical fertilizers and pesticides has a range of detrimental effects on the soil microflora of [the] agricultural ecosystem”.

Plastics and chemicals no doubt have contributed many a convenience to modern life. When it comes to the possible dangers they present to male fertility, though – even those at the microbial level in the soil of a farm on the other side of the country – cautionary measures to protect your assets would seem the wisest path.