Microplastics have been found at the summit of Mount Everest, in the Mariana Trench of the Pacific Ocean, and now in the testicular tissue of men. Recent research indicates that microplastics may be one of the causes of declining sperm quality.
From plastic bags and bottles to water sources and even the air we breathe, humans are daily confronted with the risk of microplastic contamination – a potential carcinogen and a contributor to reproductive issues. A study by scientists at the University of New Mexico (USA) discovered 12 types of microplastics in all 23 samples of male testicular tissue. The most common type found was polyethylene – the polymer used in plastic bags and bottles.
Scientists suspect microplastics are causing a decline in sperm quality. (Illustrative photo).
The average concentration of microplastics found was 329.44 micrograms per gram of tissue – significantly higher than recent studies of human blood, which reported only a few dozen micrograms per gram. This result surprised Dr. Xiaozhong John Yu, the lead author of the study: “When I first received the results from the study on dogs, I was very surprised. But I was even more surprised when I received the results from the human study.”
This research was published in the journal Toxicological Sciences, stemming from a question posed by Matthew Campen, a professor at the University of New Mexico College of Pharmacy, to Dr. Yu: “Have you ever thought about why reproductive potential has declined recently? There must be something new going on.” Previously, Professor Campen had found alarming levels of microplastics in human placentas.
Even more concerning, the study on male dog testicular samples showed that the volume of polyvinyl chloride (PVC) – a plastic commonly used in piping – was directly related to a decrease in sperm count. Although it is not yet possible to ascertain sperm counts in humans due to preservation method limitations, Dr. Yu is worried that: “PVC can release many chemicals that interfere with spermatogenesis and contains endocrine-disrupting chemicals.“
Medical experts have been concerned about declining sperm counts in men for many years. A study published in November 2022 in the journal Human Reproduction Update – which synthesized data from men in 53 countries – showed that the average sperm count has declined by 51.6% globally from 1973 to 2018. A report in 2022 also warned that the decline in sperm counts among men is a global crisis that “could threaten the survival of the human race.”
Despite concerns about the risks posed by microplastics, Dr. Yu remains cautious: “We have a lot of unknowns. We need to seriously consider the potential long-term impacts. Could microplastics be one of the contributing factors to this decline?”
