Polyethylene-based microspherules in toothpaste. Credit: Dantor
Key points:
- Researchers used a new analytical tool to measure microplastics present in human placentas.
- The study results show microplastics in all 62 of the placenta samples tested.
- The team is particularly concerned about the findings as placentas seem to become polluted in the short 8 months it grows—compared with other life-long organs.
Recent research has found microplastics in virtually everything, from water to food to our bodies. Now a new study from University of New Mexico (UNM) researchers adds to that list.
The scientists used a new analytical tool to measure microplastics present in human placentas, finding the tiny pollutants in all 62 of the placenta samples tested with concentrations ranging from 6.5 to 790 micrograms per gram of tissue.
For the study, the UNM team analyzed donated placenta tissue. In a process called saponification, they chemically treated the samples to “digest” the fat and proteins into a kind of soap. Then, they spun each sample in an ultracentrifuge, which left a small nugget of plastic at the bottom of a tube. Next, they put the plastic pellet in a metal cup and heated it to 600 degrees Celsius, then captured gas emissions as different types of plastic combusted at specific temperatures.
The results, published in XX, show that the most prevalent polymer in placental tissue was polyethylene, which is used to make plastic bags and bottles. It accounted for 54% of the total plastics. Polyvinyl chloride (better known as PVC) and nylon each represented about 10% of the total, with the remainder consisting of nine other polymers.
Study author Marcus Garcia said that, until now, it has been difficult to quantify how much microplastic was present in human tissue. Typically, researchers would simply count the number of particles visible under a microscope, even though some particles are too small to be seen.
“With the new analytical method, we can take it to that next step to be able to adequately quantify it and say, ‘This is how many micrograms or milligrams,’ depending on the plastics that we have,” Garcia explained.
Team leader Matthew Campen said the concentration of microplastics in placentas is particularly troubling—compared with other organs like the kidney—because the tissue has only been growing for eight months.
“Other organs of your body are accumulating over much longer periods of time,” he said. “And [microplastic pollution] is only getting worse. The trajectory is it will double every 10 to 15 years. So, even if we were to stop it today, in 2050 there will be three times as much plastic in the background as there is now—and we’re not going to stop it today.”