Microplastics have been found on the top of Mount Everest, at the bottom of the ocean and now in human semen.
Scientists discovered eight types of the tiny, cancer-causing plastics in all 36 men tested in the new study, including those used in Styrofoam and pipes.
Sperm samples found with particles used in pipes had less mobile sperm, which the team believes could link microplastics to global declines in fertility prices.
The chemicals that seep from these tiny particles can cause inflammation in the body that disrupts sperm quality, the researchers wrote.
The toxins have now been found in every major human organ and body part, including the brain, heart, arteries and genitals of men.
The tiny pieces of microplastic, seen here as the black dots, were found in the semen samples of all 36 participants in the Chinese trial. Pictured is polystyrene, which is used in electronics, food packaging, construction and medical products
“Microplastics are now ubiquitous, permeating ecosystems around the world, from the deepest ocean to pristine mountain regions,” the researchers wrote in their paper, which was published in the journal journal Science of the Total Environment.
The particles, smaller than five millimeters long, enter our bodies through plastic packaging, certain foods, tap water and even the air we breathe – and have been linked to cancer and fertility problems.
By collecting samples from 36 participants, researchers at Qingdao University in China hoped to determine whether these particles are common in semen.
To qualify, participants had to be in good health and not work in an industry that would expose them to more plastic than the average person.
The samples were mixed with a chemical solution, filtered and analyzed by scientists using a sensitive microscope.
The microscope and subsequent testing identified all the different chemicals present in a sample, weeding out the chemicals unique to plastics.
They found at least one of eight different types of plastic in every sample tested.
The most common type of plastic they found was polystyrene, the same material used to make packaging foam. Researchers also found plastics such as polyvinyl chloride (PVC) used to make plumbing systems.
People who had PVC in their semen had less mobile sperm than people with polystyrene alone. Less mobile sperm are generally worse at fertilizing eggs.
The sperm count in each sample did not differ significantly based on the type of plastic a person had in their system.
Previous research has suggested that the toxic particles may be released when microwaving food in plastic packaging, drinking from plastic water bottles or breathing air containing, for example, small pieces of shredded plastic from car tires.
All told, some research has suggested that the average person ingests about five grams of plastic particles per week, which is about the weight of a credit card.
These tiny particles travel through our system, likely through our bloodstream, Tracey Woodruff, director of the Program for Reproductive Health and the Environment at the University of California, San Francisco, told Scientific American.
“With all the places in your body that your blood supplies, this is an opportunity for (microplastics) to spread into different tissues,” Dr. Woodruff explains.
Although researchers previously thought that some of our more valuable body systems, such as the placenta, were impenetrable to these invaders, science has discovered that they can invade almost any part of our bodies.
Just a few weeks ago, researchers discovered the particles in the testicles of men. They have also been found in the heart, lungs and brain.
Because scientists have only recently started researching microplastics, they haven’t yet come to a consensus about what they do to us.
Previous research has shown that on average, people ingest around five grams of plastic per week, the equivalent of a credit card – and these particles accumulate in certain organs, tissues and even in the blood.
But some theorize that the chemicals these plastics produce may affect fertility. “The widespread presence of these pollutants is alarming, especially because of the implications they may have for men’s reproductive health,” the researchers wrote in the new paper.
Polystyrene interrupted the way male mice produced sperm, a 2021 study found.
When researchers introduced the plastic into the mouse’s system, it caused the testicles to become inflamed, reducing both the quantity and quality of sperm produced.
A review from 2022 from UCSF, which looked at older animal studies, suggested that microplastics may be toxic to the reproductive system and disrupt the way our bodies produce sperm and eggs.
The researchers cautioned that their study did not prove that plastics cause these in relation to reproductive trends. Other theories for the global decline in sperm counts – such as cell phone use or vape pens – are still being investigated.
But, the researchers wrote, there is an “urgent need” to continue investigating how microplastics can affect our health.
They wrote that their article is a “call for increased scientific research and public awareness regarding the potential reproductive hazards of microplastics, highlighting the importance of protecting human health from the insidious threat of environmental pollutants.”