A study by researchers at the University of New Mexico found 12 types of microplastics in all 23 human testicles and 47 dog testicles tested. Human testicles had 330 micrograms of plastic per gram of testicle tissue, which is almost three times higher than in dogs. During the research, they found microplastics in every sample. They found an average of 329.44 micrograms of microplastics per gram in humans and about 122.63 micrograms per gram in dogs. This concerning discovery has raised worries about the potential impact of microplastics on male fertility.
The human testicles were preserved, so their sperm count could not be measured. However, the sperm count in the pet dogs shows that high microplastic contamination correlates with a decrease in sperm count. Further research is needed to confirm the effect of microplastics on human sperm counts.
Microplastics have recently discovered in human body parts such as blood, breast milk and placenta indicates that there is widespread contamination of human bodies with this microplastics. In laboratory, studies have shown to cause damage to human cells. However, the impact on health is as yet unknown.
Xiaozhong “John” Yu, MD, PhD, MPH, a research team leader and a professor in the UNM College of Nursing, reported finding 12 types of microplastics in all 23 human testicles and 47 dog testicles. The most common type of plastic found in testicles was polyethylene, which is commonly used in bottles and plastic bags. PVC (polyvinyl chloride) was also identified.
“Initially, I doubted whether microplastics could enter the reproductive system,” Yu explained. “I was surprised when I saw the results for dogs and even more astonished when I saw the results for humans.”
This research contributes to the growing evidence that microplastics are widespread in our environment, infiltrating even the most delicate parts of the human body. More research is necessary to pinpoint the specific impacts of microplastics on male fertility, but this finding highlights a significant public health issue.
Although the human tissue could not be tested for sperm count, the researchers did examine this aspect in the canine samples. They discovered that higher levels of polyvinyl chloride (PVC) plastic were associated with a reduced sperm count in the dogs.
Since PVC is commonly used in numerous industrial and household products, there is a concern that plastic might be contributing to the global decline in sperm counts. This decline has already been linked to heavy metals, pesticides, and various chemicals. However, the PVC-related results observed in dogs need to be replicated in humans to determine if the same effect occurs. “The type of plastic matters – it might be correlated with potential function,” says Yu.
“PVC can release numerous chemicals that interfere with spermatogenesis and cause endocrine disruption.” The research team was eager to compare canine and human testes due to several biological similarities between the species and because dogs live alongside humans in similar environments. The long-term effects of microplastics on the human body are still uncertain, though previous studies have linked them to severe inflammatory responses and digestive system issues.
“When I first received the results for dogs I was surprised. I was even more surprised when I received the results for humans.”
While the human tissue couldn’t be tested for sperm count, the researchers did do this for the canine samples. They found higher levels of polyvinyl chloride (PVC) plastic correlated to a lower sperm count in the animals.
Whether considering the human body or the natural world, all this synthetic, non-biodegradable material likely isn’t beneficial. The real question is whether it’s already too late to address and remove it.
“We’re not trying to alarm people,” says Yu. “Our goal is to provide scientific data and raise awareness about the prevalence of microplastics.” We can choose to better avoid exposure to microplastics through lifestyle modifications and behavioral changes.
The testes examined were sourced from postmortem examinations conducted in 2016, with the individuals ranging in age from 16 to 88 at the time of their passing. Yu noted that with the current prevalence of plastic in the environment, the potential impact on younger generations could be even more alarming.
The research has been released in TOXICOLOGICAL SCIENCE
The study, featured in the journal Toxicological Sciences, involved dissolving tissue samples to analyze the residual plastic. The dogs’ testes were acquired from veterinary practices that performed neutering surgeries.
