Microplastics were found in every human placenta tested in a study, raising concerns among researchers about the potential health effects on developing fetuses.
The scientists analyzed 62 tissue samples from the placenta and found that the most common plastic was polyethylene, which is used to make plastic bags and bottles. A second study revealed microplastics in all 17 human arteries tested and suggested the particles may be linked to blood vessel blockage.
Microplastics have also recently been discovered in human blood and breast milk, indicating widespread contamination of people’s bodies. The impact on health is still unknown, but it has been shown in the laboratory that microplastics cause damage to human cells. The particles can settle in tissue and cause inflammation, as particles from air pollution do, or chemicals in the plastics can cause damage.
Huge amounts of plastic waste are being dumped into the environment and microplastics have polluted the entire planet, from the top of Mount Everest to the deepest oceans. People are known to consume and inhale the tiny particles through food and water, and they have been found in the feces of babies and adults.
Professor Matthew Campen from the University of New Mexico, US, who led the research, said: “If we see effects on the placenta, all mammalian life on the planet could be affected. That is not good.”
He said the growing concentration of microplastics in human tissue could explain a puzzling increase in some health problems, including inflammatory bowel disease (IBD), colon cancer in people under 50 and declining sperm counts. A 2021 study found that people with IBD had 50% more microplastics in their stool.
Campen said he was very concerned about growing global plastic production as it meant the problem of microplastics in the environment was “only getting worse”.
The research, published in the Toxicological Sciences magazine, found microplastics in all placental samples tested, with concentrations ranging from 6.5 to 790 micrograms per gram of tissue. PVC and nylon were, after polyethylene, the most commonly found plastics.
The microplastics were analyzed by using chemicals and a centrifuge to separate them from the tissue, then heating them and analyzing each plastic’s characteristic chemical signature. The same technique was used by scientists at Capital Medical University in Beijing, China to detect microplastics in the human artery samples.
Microplastics were first discovered in placentas in 2020, in samples from four healthy women who had normal pregnancies and births in Italy. The scientists said: “Microplastics carry substances that, as endocrine disruptors, can cause long-term effects on human health.”
The concentration of microplastics in the placentas was particularly worrying, Campen said. The tissue only grows for eight months, while it begins to form about a month into pregnancy. “Other organs of your body build up over much longer periods of time,” he added.