Microplastics have been found on the top of Mount Everest, at the bottom of the ocean and now in human sem*n.
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.
sem*n samples found with particles used in piping had less mobile sperm, which the team suggested may link microplastics to the global decrease in fertilityrates.
The chemicals that leech from these tiny particles could 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 bits of microplastic, seen here as the black dots, were found in the sem*n samples of all 36 participants in the Chinese trial. Pictured isPolystyrene, which is used inelectronics, food packaging, construction and medical products
'Microplastics are now ubiquitous, and they permeate ecosystems globally, from the deepest ocean to pristine mountain regions,' the researchers wrote in their paper, which was published in the journal Science of The Total Environment.
The particles, smaller than five millimeters in length, enter our bodies through plastic packaging, certain food, tap water and even the air we breathe - and have been linked to cancer and fertility issues.
By collecting samples from 36 participants, researchers from Qingdao University in China hoped to determine whether or not these particles are commonly found in sem*n.
In order to qualify, the participants had to be in good health and not work in an industry that would expose them to more plastics 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 tests, identified all the different chemicals present in a sample - singling out those unique to plastics.
In every sample tested, they found at least one of eight different kinds of plastic.
The most common type of plastic they found was polystyrene, which is the same material used to make packaging foam. Researchers also found plastics likepolyvinyl chloride (PVC) that is used to make plumbing systems.
People who had PVC in their sem*n had less mobile sperm than those with only polystyrene. Less mobile sperm, generally, is worse at fertilizing eggs.
The sperm count in each sample didn't differ significantly based on the kind of plastic someone had in their system.
Previous research has suggested that the toxic particles can be released whenmicrowaving food in plastic packaging, drinking from plastic water bottles or breathing in air that has, for example, tiny bits 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 roughly the weight of a credit card.
These tiny particles travel through our system, likely through our bloodstream,Tracey Woodruff, the director of the Program on Reproductive Health and the Environment at the University of California, San Francisco, told Scientific American.
'With all of the places in your body that are being supplied by your blood, it’s an opportunity for [microplastics] to diffuse into different tissues,' Dr Woodruff explained.
Though researchers previously thought some of our more precious bodily systems, like the placenta, were impermeable to these invaders, science has found that they can get into almost every part of our body.
Just weeks ago, researchers discovered the particles in men's testicl*s. They've also been found in the heart, lungs and brains.
Because scientists have only begun investigating microplastics in the recent past, they haven't come to a consensus about what they are doing to us.
Previous research has shown that, on average, people ingest about five grams of plastic every week, the equivalent of a credit card - and these particles are accumulating in certain organs, tissues and even in the blood
But some theorize that the chemicals these plastics produce could be affecting fertility.'The widespread presence of these contaminants is alarming, mainly due to the implications they may have on male reproductive health,' the researchers in the new paper wrote.
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 testicl*s to become inflamed, which reduced both the amount and quality of sperm produced.
A 2022 reviewfrom UCSF that looked at older animal studies suggested that microplastics might be a toxic to the reproductive system - interfering with the way that our body produces sperm and eggs.
The researchers cautioned that their review hasn't proven that plastics are causing these concerning reproductive trends. Other theories for the global decrease in sperm count - like cell phone use or vape pens - are still being investigated.
But, the researchers wrote, there is a 'pressing need' to continue investigating how microplastics may be impacting our health.
They wrote that their paper is a 'call for increased scientific scrutiny and public awareness regarding the potential reproductive hazards of microplastics, emphasizing the importance of safeguarding human health against the insidious threat of environmental contaminants.'
