Microplastics, pieces of plastic less than 5 millimeters long, have been found practically everywhere. Scientists have discovered them as far as the arctic ice and as deep as the deep sea trenches, and even in human placentas. And now, recent research has uncovered their presence in men’s testicles. Dr. John Yu, a toxicologist in the College of Nursing at the University of New Mexico and lead author of this new study, did not expect to see microplastics in men’s reproductive systems, considering the extensively tight blood-tissue barrier around those organs. Yu and his research term uncovered heavy concentrations of microplastics in the testicles of about two dozen men and nearly 50 dogs.
For this study, researchers collected the testicles from the autopsies of men ages 16 to 88. The dog specimens were gathered from dogs neutered by local veterinarians. Researchers determined the amount of plastic by dissolving the biological tissue and sorting out the remaining solids. Microplastics constituted 75% of what remained. The plastics found included polyethylene (PE), the most used plastic in the world, often serving as packaging material, and polyvinyl chloride, which is in PVC piping. Polyvinyl chloride was the second most common plastic found in the dog samples of the study and is a known carcinogen. Dr. Yu and his team uncovered a direct correlation between PVC and lowered sperm count thanks to their canine sampling. Due to storage issues, researchers could not perform a similar analysis on the human samples.
The number of microplastics in the testicles was higher than that found previously in human placentas and second to the quantity discovered in the human brain. While the preliminary results cannot prove a relationship between fertility and microplastics, emerging research shows that the correlation may soon shift from “suspected” to “likely.”
While the research is still early, the connection between microplastics and male infertility is becoming more evident. This study adds to growing evidence of how the environment affects our reproductive health.