Scientists say hormonal changes caused by microplastics exposure may be one explanation for declining male fertility rates.

Human testicles may contain high concentrations of microplastics and nanoplastics, substances that can interfere with the reproductive system, a new study suggests.

For the study, scientists tested levels of 12 different types of plastic in 23 testes taken from male cadavers that ranged in age from 16 to 88 years old at the time of death.

The average concentration of microplastics in testicular tissue taken was 329.44 micrograms per gram of human testicular tissue, according to study results published in Toxicological Sciences.

Scientists found that the most common plastic found in both human testicular tissue was polyethylene, which is used to make plastic bags and bottles.

Microplastics and Nanoplastics Are Basically Unavoidable

“Microplastics and nanoplastics are everywhere,” says a co-author of the study, Matthew Campen, PhD, a professor and the director of pharmaceutical sciences at the University of New Mexico in Albuquerque who studies environmental toxins.

“We do not have solid data linking the plastics to health outcomes yet,” Dr. Campen adds. “But the declining global sperm count parallels the emergence of microplastics across the globe.”

Microplastics and nanoplastics are far too tiny to detect as you go about your daily life, being less than 5 micrometres in size – thousands of times smaller than a grain of rice – and nanoplastics are below 1 micrometre.

These minuscule plastics are found in everything from food and drink containers to clothing and furniture.

They are in the air we breathe, the food we eat, and the water we drink – and once they enter our bodies, they can invade cells in tissues and organs and remain there forever.



How Do Microplastics Affect Reproductive Health?

Microplastics are known as endocrine disruptors because they can interfere with the human reproductive system, contributing to structural problems with the genitals, infertility, and a reduced sperm count, according to the Endocrine Society.

Over the last half century, as microplastics have become more ubiquitous, sperm counts in the United States and many other parts of the world have declined by at least 50 percent, according to the Endocrine Society.

“Microplastics have been measured in every human tissue, including human breast milk, blood, placenta, and stool, and now testes,” says Tracey Woodruff, PhD, MPH, a professor and the director of the program on reproductive health and the environment at the University of California in San Francisco. “So it is not surprising that they were found there, but it certainly is concerning.”

It’s also not surprising that polyethylene was the plastic most commonly found in human testicular tissue, because it’s the most commonly produced plastic, says Dr. Woodruff, who wasn’t involved in the new study.

There’s no sure fire way to entirely avoid exposure to microplastics, Woodruff adds. “The best protection is systemic changes from public policies that reduce the production and use of plastics. We have plenty of plastics in our lives,” Woodruff says. “Unfortunately, the plastic production is expected to triple by 2060.”

SOURCE: Everyday Health