Microplastics: The latest killer of male fertility?

A study published in Toxicological Sciences last week has raised concerns that microplastics are affecting male fertility.

Microplastics in every testicle

Researchers from the University of New Mexico set out to discover how microplastics can affect sperm count. They looked at 47 dog testes and 23 human testes, and found microplastics in every one. The most common plastic found in the testes was polyethylene, which is found in plastic shopping bags and some bottles. PVC was the second most prevalent microplastic found in the testicles.

Because the human testicles had been preserved, sperm count could not be measured. In the canine testes, however, the researchers found that higher concentrations of microplastics were associated with lower sperm counts.

“These findings highlight the pervasive presence of microplastics in the male reproductive system in both canine and human testes, with potential consequences on male fertility,” wrote the researchers.

The research represents the latest finding about a continuing decline in male fertility.

Insecticides

A study published last year found that sperm count in men around the world has decreased by 50% over the last 50 years. Pesticides have been determined to play a major role.

The researchers conducted a meta-analysis looking at 1,774 men across 20 studies and 21 study populations. They were specifically looking for any impact on male fertility from organophosphates (OPs) and N-methyl carbamates (NMCs), two of the most common insecticides.

“They are widely used in agriculture on the crops we eat,” said Melissa Perry, one of the study’s authors. “We use them in structural applications within homes and buildings, apartment buildings, as well as for ornamental lawn upkeep. They’re available for consumer purchase so organophosphate exposures have been demonstrated to be relatively widespread.”

In addition to killing insects, OPs are also used in nerve gas and plastics and are known to cause neurodevelopmental harm to children.

Rather than analyze overall sperm count, which is the number of sperm in an entire ejaculate, the study looked at the men’s sperm concentration, which is measured as the number of sperm per milliliter of semen. The researchers felt this would adjust for variabilities in semen volume.

They found a high association between the insecticides and low sperm concentration, with OPs appearing to be even more dangerous than NMCs. 

“Based on the results of this investigation, the strength of evidence of an association between higher adult OP and NMC insecticide exposure and lower sperm concentration is sufficient enough to warrant concern, particularly in light of observed downward trends in semen quality,” concluded the authors.

Men who had occupational exposure to the insecticides — those who work in agriculture, for example — predominantly had lower sperm concentrations. But “even a small magnitude of effect could have consequential impacts on sperm concentration at a population level,” explained the researchers.

Pesticide found in water supply feminizes males

Other pesticides are also known to impact male fertility. 

In one study, researchers from the University of California, Berkeley found that three-quarters of male frogs exposed to atrazine began producing less sperm and less testosterone. Not only did the frogs experience lower fertility, many sought to mate with males instead of females. Ten percent of the frogs exposed to atrazine became females producing viable eggs.

“Atrazine-exposed males were both demasculinized (chemically castrated) and completely feminized as adults,” wrote the researchers.

Approximately 80 million pounds of atrazine are used in the US every year. It is found on crops and has often been detected in the country’s water supply.

COVID-19 mRNA vaccines affect male fertility 

But microplastics and pesticides are not the only prevalent toxins impacting men’s reproductive health. CNN reports several factors that may be causing this “public health issue”:

It’s not just pesticides. Researchers are exploring the role of obesity, poor diet, chronic disease and exposure to environmental toxins such as pollution, PFAS and other potential toxins. Some are even looking at radiation from mobile phone use as a potential reason for the precipitous drop in sperm count.

CNN failed to mention that researchers have also found COVID-19 mRNA injections impact male fertility. More than 70% of the world’s population — over 5.5 billion people — have been injected.

A peer-reviewed study of young Israeli men published in 2022 showed that between two and four months after the Pfizer vaccine, “Covid-19 vaccination BNT162b2 temporarily impairs semen concentration and total motile count among semen donors.” The effect was described as “temporary” because it appeared to return to near-normal levels after approximately five months.

However, while claims that the study showed “recovery” at around five months post-vaccination may be accurate for some trial participants, they were certainly grossly inaccurate for at least a quarter of them — their parameters continued to decline, often significantly.

Virtually all studies claiming to show that mRNA injection does not impair fertility stop two months after the second dose. It is unclear if this is by design so as not to reveal another adverse event, but top scientists who have asked such questions have been suppressed.