A recent study from the University of New Mexico Health Sciences found that microplastics are present in virtually everything we consume, from bottled water to meat and plant-based food. Researchers have used a new analytical tool to measure the microplastics present in human placentas.
In a study published on February 17 in Toxicological Sciences, led by Dr. Matthew Campen from UNM, microplastics were found in all 62 placenta samples tested. Concentrations ranged from 6.5 to 790 micrograms per gram of tissue.Â
Despite their small size (a millionth of a gram), Campen is concerned about the increasing amount of microplastics in the environment and its potential health effects.
Matthew Campen said, For toxicologists, “the dose makes the poison. If the dose keeps going up, we start to worry. If we see effects on placentas, then all mammalian life on this planet could be impacted. That’s not good.”
Campen and his team, with the help of colleagues at the Baylor College of Medicine and Oklahoma State University, examined donated placenta tissue. They subjected the samples to saponification, where chemicals break the fats and proteins into soap-like substances.
They centrifuged each sample using an ultracentrifuge, resulting in a tiny plastic residue settling at the tube’s base. Then, employing pyrolysis, they placed the plastic pellet within a metal cup and subjected it to 600 degrees Celsius, capturing gas emissions as distinct plastic types combusted at precise temperatures.
Campen said, “The gas emission goes into a mass spectrometer and gives you a specific fingerprint. “It’s cool.”
The researchers found that polyethylene, commonly used in plastic bags and bottles, was the most common polymer in placental tissue, making up 54% of the total plastics. Polyvinyl chloride (PVC) and nylon accounted for around 10%, while the rest comprised nine other polymers.
Marcus Garcia, a postdoctoral fellow in Campen’s lab who performed many experiments, noted the difficulty in quantifying microplastic in human tissue until now. Previously, researchers focused on counting visible particles under a microscope, though some were too small to see.
Plastic usage globally has surged since the 1950s, generating a ton of plastic waste per person worldwide. While a third of produced plastic remains in use, most end up discarded or in landfills, where exposure to sunlight’s ultraviolet radiation begins to break it down.
Garcia said, “That ends up in groundwater, and sometimes it aerosolizes and ends up in our environment. We’re getting it not only from ingestion but also through inhalation. It affects us as humans and all of our animals – chickens, livestock – and plants. We’re seeing it in everything.”
Campen explains that plastics take time to break down, up to 300 years, but some degrade over time. Microplastics found in the environment today could be 40 or 50 years old.
As microplastics are already present in our bodies, their health effects are unclear. Some microplastics are tiny in size and are measured in nanometers to pass through cell membranes. According to Campen, an increase in the presence of microplastics in human tissue might be linked to rising health issues like inflammatory bowel disease, colon cancer, and a decrease in sperm count.
The high amount of microplastics in placentas is a concerning issue as tissue only develops over eight months, much shorter than other organs that accumulate pollutants over more extended periods. Campen and his team plan more research to address these concerns. At the same time, he’s warned about the increasing plastic production worldwide.
Journal reference:
- Yoshikazu Yamagishi, Sayaka Nagasawa, et al., Evaluation of organophosphorus pesticide tyrosine adducts for post-mortem change by human serum albumin with liquid chromatography quadrupole orbitrap mass spectrometry. Toxicological Sciences. DOI: 10.1093/toxsci/kfae023.