In February, scientists discovered a spoonful of microplastics lurking in human brains.
Previous research detected the tiny particles in our lungs, liver, kidneys and blood — plus in bodily fluids like semen and breast milk.
Now a study published in Ecotoxicology and Environmental Safety has found that in yet another part of the body, which researchers say “should serve as an important warning signal.”
Luigi Montano and his team at the University of Rome discovered microplastics in the ovary follicular fluid of 14 out of 18 women they studied.
Follicular fluid surrounds eggs developing in the ovaries, delivering nutrients like glucose, triglycerides, fatty acids, albumin and globulin.
“As far as we know, this is the first study to provide evidence for [microplastics’] presence in ovarian follicular fluid in women undergoing assisted reproductive treatment,” said the study’s authors.
“This discovery should serve as an important warning signal about the invasiveness of these emerging contaminants in the female reproductive system, considering that they can alter its composition and have an impact on the oocyte [egg], thus posing a significant reproductive risk for our species.”
Montano said their findings were “very alarming,” noting that his previous research also suggests that microplastics lower sperm count and quality.
He told The Guardian that it’s not just the microplastics themselves that may be doing damage to fertility, calling them a “Trojan horse” allowing bisphenol, phthalates, PFAS — AKA forever chemicals linked to cancer and hormonal disruption — to get into the body.
Microplastics and fertility
While this is the first study to find microplastics in the ovaries, they have previously been observed in the uterus and placenta.
They’ve also been found in human testicles — at alarming amounts.
“The levels of microplastic shards and types of plastics in human testes were three times greater than those found in dogs, and the dogs are eating off the floor,” Matthew Campen, a toxicologist and co-author of a 2024 study on microplastics in the testes, told CNN.
“So it really puts in perspective … what we’re putting in our own bodies.”
A key fear is that microplastics are endocrine disruptors, meaning they mess with hormones. This can have a major impact on lots of the bodies functions, especially fertility and reproduction.
How do microplastics get into our bodies?
There are two main ways human bodies get contaminated with microplastics: by breathing them in the air or by eating them in food.
One of the big issues, say experts, is that so much of our food is stored at some point in plastic containers or bags.
“Not only is it packaged in plastic when we buy it from the store, but then we cook it, and we often put it in plastic containers to store it in our fridge, because it’s easy and it’s cheap,” Victoria Fulfer, a postdoctoral fellow at the University of Rhode Island who studies microplastics, told NBC News. “And that plastic is leaching into our food.”
While that leaching appears to happen from any contact, it gets worse when those plastic containers are heated up.
“Mostly, when a container says ‘microwave safe,’ it means it’s safe for the container to be in the microwave — it’s not going to melt,” she said.
“But that doesn’t mean that it’s safe for you as a person, because microwaving plastic particularly changes the chemical bonds — they make them more weak. And that allows any chemicals that are in those plastics, and also nanoplastics, to leach from that container into the food that you’re heating up.”
It doesn’t even have to be reheated in the microwave — simply storing hot food in plastic has been shown to have risks, even beyond those from microplastics.
In December, Chinese researchers found that rats that drank water which had been boiled and placed in a plastic takeout lid had significant inflammation and damage to their heart muscles.
What can we do to reduce microplastic intake?
Unfortunately, microplastics — tiny pieces up plastic up to 5 millimeters long — are ubiquitous, with estimates that 10 to 40 million metric tons of them are let loose into the environment every year.
Researchers have found that people consume about 5 grams a week, or enough to fill a soup spoon. In a year, that’s 250 grams — a “heaped dinner plate’s worth,” according to Reuters.
To cut down a bit on your microplastic intake, experts recommend not drinking out of plastic water bottles, avoiding plastic tea bags, boiling and filtering tap water, ditching plastic cutting boards, and keeping plastic containers out of the microwave.
“Given the widespread presence of microplastics in the environment, completely eliminating exposure is unrealistic. A more practical approach is to reduce the most significant sources of microplastic intake,” researchers behind one water bottle study wrote in Genomic Press.
