The price we pay for living in an industrial civilization is reading alarming news about pollutants, from PCBs to PFAS to microplastics. Microplastics, extremely small pieces of plastic debris that flake off of industrial waste and plastic consumer products, are believed to be causing adverse health effects in nearly every form of life on Earth that they touch. Yet there's an even bigger threat to human health that is, paradoxically, smaller in size: nanoplastics.
Researchers fed five pregnant rats nanoplastics, focusing on the potential effect of ingesting such pollutants.
As the "nano-" prefix implies, nanoplastics are very small pieces of plastic, less than 100 nanometers in size, that are released into the environment as a result of plastic disintegration. It is currently estimated that an estimated six billion metric tons of plastic waste has been deposited in the environment. While nanoplastics have been identified in our collective food chain, and some research has shown that they can affect marine life, their ability to traverse the placenta and affect the unborn not been widely studied — until now. Last month, researchers at the Rutgers School of Public Health published a study that found nanoscale plastic particles can translocate from pregnant rats to their unborn fetuses. The study has frightful implications for transmission of tiny plastic particles between mother and baby.
"These plastic materials, when they end up in environmental media, they start breaking into smaller pieces over time," Dr. Philip Demokritou, the Henry Rutgers Chair and professor in nanoscience and environmental bioengineering at the Rutgers School of Public Health, told Salon. "After 50-60 years, they are everywhere, they are in the water you drink, even the air you breathe, because we also incinerate plastic materials. We are still assessing how they behave, how they interact with biological systems, and if they can cause adverse health effects."
Researchers fed five pregnant rats nanoplastics, focusing on the potential effect of ingesting such pollutants. Twenty-four hours later, they used an imaging technique known as "enhanced darkfield hyperspectral microscopy" to locate the materials within the rats and see if they were able to pass through the gastrointestinal tract and the placenta and reach the unborn fetus.
Upon examination, the researchers not only found the particles in the pregnant rats' placentas, but they were also in their livers, kidneys, hearts, lungs and brains of their fetuses.
"That's a very critical window," Demokritou said. "If the fetus is getting exposed, that can resolve developmental effects."
While much remains unknown, Demokritou said the results of the study are "certainly cause for concern," and that follow-up research is needed. Indeed, this is the first study confirming transmission of ingested nanoplastics to fetal tissues in a mammalian species. Though humans have yet to be studied, the findings certainly raise questions as to whether nanoplastics reach unborn human fetuses. Notably, previous research found microplastics present in human placentas.
Previous research has found tiny plastic particles present in human lungs and blood.
According to a separate paper published in the peer-reviewed journal Nanomaterials, nanoplastics pose several ecological and toxic risks to human health. Laundry wastewater, car tires, drinking water and air inhalation are major sources of nanoplastics. Previous research has shown that nanoplastics can lead to biological cellular death — but factors such as the type of nanoplastic determine impact.
Moreover, previous research has found tiny plastic particles present in human lungs and blood. However, as a research paper from Environmental Health Perspectives highlighted: "the impacts of plastic particles are unexplored, especially with regard to early life exposures." When it comes to maternal-fetal health, part of the problem is that it is ethically challenging to study the direct impact.
Demokritou emphasized to Salon that "not all nanoparticles are created equal," which was reflected in the study as the researchers focused on a polystyrene material kind of nanoplastic.
Polystyrene, Demokritou said, is the kind of plastic "used to make your takeaway plates." Demokritou said that researchers "need to continue studying" the affects of this and other plastics on humans.
Animal studies do not always translate to humans, but researchers in this case believe that the data does suggest that humans are experiencing similar nanoplastic transmission.
"We are pretty good at extrapolating data from animal models to humans," Demokritou said, adding that with the evidence that microplastics have already been found in human placentas, it's possible. "We have reason to believe that this is what's happening in real life."
