Concerning concentration of microplastics found in human testes, study finds

Researchers at the University of New Mexico found a significant concentration of microplastics in human testicles, adding to concerns about the lasting impact the tiny particles can have on our bodies.

The discovery was made when the group of scientists examined tissue samples from 23 human testes, obtained from the New Mexico Office of the Medical Investigator, and 47 canine testes from local animal shelters and clinics that perform spay and neuter operations. One of the reasons the team decided to use canine samples in their research is that dogs live alongside people in shared environments.

A dozen types of microplastics were found in all of the samples, according to their findings that were recently published in the journal Toxicological Sciences.

The most prevalent in both the human and canine tissue samples was polyethylene, which is used to make plastic bags and bottles. PVC was the second most common type found in the dog samples — a material most often used in plumbing.

The average concentration of microplastics found in the human testicles was 329.44 micrograms per gram — nearly three times higher than the amount found in the canine samples, the researchers said.

The team also noted that a higher level of PVC particles in the canine samples correlated with a lower sperm count. Since the human samples were chemically preserved, a sperm count could not be conducted.

There was no connection between the amount of polyethylene and sperm count, the study said.

“PVC can release a lot of chemicals that interfere with spermatogenesis and it contains chemicals that cause endocrine disruption,” explained Dr. Xiaozhong “John” Yu, a university professor who led the study.

Yu noted that the average age of the men in the samples was 35, which means their exposure to the microplastics began before the material became widely circulated, and the impact on younger generations could be more concerning.

The impulse for this study came after Yu spoke with his colleague Dr. Matthew Campen about his recent research documenting microplastics in human placentas.

Yu said the global decline in sperm count and quality as it relates to reproduction in recent years has been correlated to heavy metals, pesticides and endocrine-disrupting chemicals. The findings in his most recent study will encourage additional research on how microplastics might affect sperm production.