A study found microplastics in dog testicles. In those of humans, he found three times more

New research has found the presence of microplastics in human testicles, leading scientists to believe the finding could be linked to reduced sperm counts in men around the world.

For the study, 23 human testicles and 47 from dogs were used, The Guardian newspaper reported.

Although in the case of human testicles the sperm concentration could not be determined because they were samples that had been preserved, in the case of dogs it was possible to determine it, and Their number was lower in those with a greater presence of microplastics.

The testicles used in the study came from autopsies performed in 2016. The age of the donors ranged from 16 to 88 years.

Plastic waste on the northern coast of Denmark.

The dogs' testicles were obtained in veterinary offices where sterilization operations were performed.

The researchers indicated that, although it is possible to establish a correlation between the presence of microplastics and the lower number of sperm, it is necessary to carry out other studies to be able to state this with certainty.

Plastic particles can lodge in tissues and cause inflammation. Last March, a group of doctors warned about the potentially lethal effects –including a substantial increase in the risk of stroke, myocardial infarction and premature death– when blood vessels suffer from the presence of microscopic plastics.

Microplastics have contaminated the entire planet. Its presence has been detected from the top of Everest to the depths of the oceans.

Have also been discovered in human blood, placentas and breast milk. Although their impact on health is still unknown, it has been shown in the laboratory that microplastics have the ability to damage human cells.

Generally, these particles reach humans through ingestion of food and water, as well as through the respiratory tract.

“At first I doubted whether microplastics could penetrate the reproductive system,” said Professor Xiaozhong Yu, from the University of New Mexico, quoted by The Guardian. “When I first received the dogs' results I was surprised. Even more so, when I received the results from humans,” he stressed.

Sperm count in men has decreased in recent decades. Many studies have pointed to chemical pollution as one of the causes.

The research was published in the journal Toxicological Sciences. The methodology consisted of dissolving the tissue samples and then observing the plastic that remained.

Among the results of the study was that The concentration of plastic in human testicles was almost three times higher than that in canines: 330 micrograms per gram of tissue versus 123 micrograms.

Polyethylene, mostly used in plastic bags and bottles, was the most common microplastic found, followed by PVC.

“PVC can release many chemicals that interfere with spermatogenesis and contains chemicals that cause endocrine disruption,” Yu explained.

Another smaller investigation in China, in 2023, also found microplastics in six human testicles and 30 semen samples.

Studies in mice have also concluded its presence reduced the number of sperm and caused alterations in hormones, concluded The Guardian.