Scientists have detected “significant concentrations” of microplastics in the testicles of both humans and dogs. Worryingly, they also found some evidence that certain forms of microplastic might be having a damaging impact on sperm count.
Researchers at the University of New Mexico looked for microplastics in 47 canine and 23 human testes taken during autopsies – they found microplastics in every single individual.
The average concentration of microplastics in the dogs’ testicular tissue was 122.63 micrograms per gram of tissue, while concentrations in human testicular tissue were 328.44 micrograms per gram.
“At the beginning, I doubted whether microplastics could penetrate the reproductive system. When I first received the results for dogs I was surprised. I was even more surprised when I received the results for humans,” Xiaozhong “John” Yu, lead author of the study and a professor at the University of New Mexico College of Nursing, said in a statement.
The researchers weren’t able to count the sperm in the human samples due to the way they had been chemically preserved, but they were able to do so with the canine samples. This revealed that higher levels of PVC, the world’s third-most widely produced synthetic polymer of plastic, in the tissue were correlated with a lower sperm count.
“PVC can release a lot of chemicals that interfere with spermatogenesis and it contains chemicals that cause endocrine disruption,” Yu explained.
Microplastics are tiny plastic particles less than 5 millimeters in size, originating from the breakdown of larger plastic debris or from products containing microbeads, such as cosmetics.
They are prevalent in the environment – from the oceans and soil, to rain and even the air – plus there’s a wealth of evidence suggesting they are pervasive in the bodies of humans. Along with coming into contact with microplastics in the surrounding environment, there are also significant quantities of the stuff in our food.
This relatively new form of pollution caught the attention of Yu, who studies the impact of various environmental factors on the human reproductive system. Much of his work has focused on how pollutants, such as heavy metals and pesticides, are impacting sperm cell production and contributing to the global decline in sperm count in recent years.
After hearing that microplastics had been found in placenta tissue, he and his team started to wonder whether a similar problem was occurring in testicles. They also have started to question whether microplastics might have something to do with the recent global decline in sperm count.
Yu said: “We have a lot of unknowns. We need to really look at what the potential long-term effect [could be]. Are microplastics one of the factors contributing to this decline?”
“We don’t want to scare people,” he added. “We want to scientifically provide the data and make people aware there are a lot of microplastics. We can make our own choices to better avoid exposures, change our lifestyle and change our behavior.”
The study is published in the journal Toxicological Sciences.
