Microplastics are now found in human placentas; what are the health impacts on our bodies?

Microplastics have been found on nearly every corner of the globe and all throughout our bodies, and scientists have become increasingly concerned about what it might entail for our health. Photo / NZME

Scientists have renewed their concerns over the extent to which microplastics are infiltrating our lives and impacting human health, particularly foetal development, after a new study detected their presence in every human placenta that was looked at.

Researchers studied a range of tissue samples taken from 62 placentas, where they detected microplastics in each one. Polyethylene, a plastic compound used to create everyday items such as plastic water bottles, glad wrap and bags, was the most prevalent plastic found.

In a separate study, researchers also found microplastics located within human arteries, which they detected in each one of the 17 arteries analysed. They concluded that microplastics could contribute to blocking blood vessels, significantly increasing the risk of experiencing heart-related issues.

Earlier research has already found microplastics in many parts of the human body, including in breast milk and blood samples, and throughout nature. To give an idea of where they come from, a study in 2022 found that, from the atmosphere alone, the equivalent of three million plastic bottles in airborne microplastics fall into Auckland from the sky each year.

Their invasive presence in our bodies and all around us highlights just how widespread microplastics have become.

Early lab research on the interaction between microplastics and human cells has shown that the fragments have a damaging effect on human health. Similar to the effects of air pollution, microplastic particles can trigger inflammation by becoming embedded in the skin. Furthermore, the chemicals found in plastics could have negative health effects.

This image shows some of the microplastics discovered in the seabed of Marlborough's Long Island-Kokomohua Marine Reserve. Image / Marta Ribó

For a plethora of reasons, plastic production and consumption exploded over the last six or so decades, and plastic waste has now become one of the most pressing environmental issues that we have ever faced. The presence of microplastics in our mountains, in the air, under our soil, within our food and beneath our oceans is a telling sign of the scale of the plastic problem we face.

“If we are seeing effects on placentas, then all mammalian life on this planet could be impacted. That’s not good,” said Professor Matthew Campen, the lead researcher of the study at the University of New Mexico.

Campen believes that the increasing number of health issues in the industrialised world - such as a rise in those with inflammatory bowel disease (IBD), declining sperm levels and a lowering average age of those diagnosed with colon cancer - could be somehow linked to the gradual increase of microplastics found in the body.

For example, a Chinese study conducted in 2021 reported a 50 per cent increase in microplastics found in the faeces of those with IBD. Establishing these linkages would be crucial to mitigating the effects of microplastics on human health.

Campen said that the plastic problem “is only getting worse” as plastic production continues to grow globally, and he seems pessimistic about seeing a change anytime soon.

Microplastic pieces are in our oceans, air and homes, and are now being found in us. Photo / 123rf

The latest study reported finding a concentration of microplastics between 6.5 to 790 micrograms per gram of tissue within the placentas analysed. Polyethylene was the most prevalent plastic compound, followed by PVC and nylon, according to the study in the Toxicological Sciences journal.

The study involved separating the microplastics from the human tissue through using a centrifuge and a chemical mixture. Then, the plastic chemical compounds were able to be detected through each of their unique heat signatures.

One of Campen’s main concerns was the level of microplastics found in the placenta, in which the tissue only grows for about eight months. “Other organs of your body are accumulating over much longer periods of time,” he said, suggesting that microplastics could have a detrimental effect when they build up over time in the body.

It isn’t the first time that scientists have detected microplastics in human placentas, although it is the most expansive study. In 2020, the placentas of four normal women who had healthy pregnancies and births were analysed, with scientists finding microplastics in all of them.

“Microplastics carry with them substances which, acting as endocrine disruptors, could cause long-term effects on human health,” said the scientists at the time.