Microplastics Found in Human and Canine Testes

In a concerning discovery, researchers from the University of New Mexico have detected significant concentrations of microplastics in the testicular tissue of both humans and dogs. The study, published in Toxicological Sciences, adds to the growing concern about the potential impact of microplastics on human reproductive health.

Led by Xiaozhong "John" Yu, the team found 12 types of microplastics in 47 canine and 23 human testes samples. Remarkably, the average concentration of microplastics in human testicular tissue was 329.44 micrograms per gram—nearly three times higher than in dogs and significantly higher than the levels found in human placentas in previous studies.

"Our study revealed the presence of microplastics in all human and canine testes," Yu said, expressing surprise at the initial findings. The most prevalent polymer found in both human and canine tissue was polyethylene (PE), commonly used in plastic bags and bottles, followed by PVC in dogs, which is used in plumbing and various other applications.

The researchers found a correlation between higher levels of PVC in canine testicular tissue and lower sperm counts, suggesting a potential impact on spermatogenesis and reproductive function. "The plastic makes a difference—what type of plastic might be correlated with potential function," Yu explained, noting that PVC can release chemicals that interfere with sperm production and cause endocrine disruption.

The study compared human and canine tissue due to the shared environment and biological similarities between the two species. Yu noted that dogs and humans share common environmental factors that contribute to the observed decline in sperm counts in both species.

Microplastics are ubiquitous in the environment, resulting from the degradation of plastic exposed to ultraviolet radiation and landfills. With the average age of the human samples being 35, Yu expressed concern about the potential impact on younger generations, as global plastic use continues to rise.

While the study does not aim to cause panic, it serves as a wake-up call for the scientific community and the public to address the pervasive issue of microplastic pollution and its potential consequences on human and animal health.