A flurry of recent studies have found that microplastics are in almost everything we consume, from bottled water to meat and plant-based foods. Now, researchers at the University of New Mexico Health Sciences have used a new analytical tool to measure microplastics in human placentas.

In a study published on February 17 in the journal Toxicological SciencesA team led by Matthew Kempen, Ph.D., Regents Professor in the UNM Department of Pharmaceutical Sciences, reported finding microplastics in all 62 placental samples tested, ranging from 6.5 to 790 micrograms per gram of tissue. was

While that number may seem small (a microgram is one millionth of a gram), Campion is concerned about the health effects of the ever-increasing volume of microplastics in the environment.

For toxicologists, “the food makes the poison,” he said. “If the dose continues to increase, we start to worry. If we’re seeing effects on the placenta, then all the mammalian life on that plant could be affected. That’s not a good thing.”

In the study, Campion and his team, in partnership with colleagues at Baylor College of Medicine and Oklahoma State University, analyzed donated placental tissue. In a process called saponification, they chemically treated the samples to “digest” the fats and proteins into a type of soap.

Then, they spun each sample in an ultracentrifuge, which left a small nugget of plastic at the bottom of a tube. Then, using a technique called pyrolysis, they put plastic pellets in a metal cup and heated it to 600 degrees Celsius, then captured the gas emissions from burning different types of plastics at specific temperatures. .

“The gas emission goes into the mass spectrometer and gives you a specific fingerprint,” Campion said. “It’s really great.”

The researchers found that the most prevalent polymer in placental tissue was polyethylene, which is used to make plastic bags and bottles. This is 54% of the total plastic. Polyvinyl chloride (better known as PVC) and nylon each represented about 10% of the total, with nine other polymers comprising the remainder.

Marcus Garcia, a postdoctoral fellow in Campion’s lab who conducted many of the experiments, said that until now it has been difficult to estimate the amount of microplastics in human tissue. Typically, researchers will only count the number of particles visible under a microscope, even though some particles are too small to see.

With the new analytical method, he said, “we can take it to the next step to quantify it properly and say ‘how many micrograms or milligrams is this,’ on the plastic we have.” depending on.”

Since the early 1950s, the use of plastic has grown exponentially worldwide, generating one metric ton of plastic waste for every person on the planet. About a third of the plastic produced is still in use, but most of the rest is discarded or sent to landfills, where it breaks down from exposure to ultraviolet rays in sunlight. starts

“It ends up in groundwater, and sometimes it aerosolizes and ends up in our environment,” Garcia said. “We’re getting it not only through ingestion, but also through inhalation. It affects not only us as humans, but all our animals — chickens, cattle — and all our plants. We Seeing it in everything.”

Campion explains that many plastics have long half-lives — the amount of time it takes for half of a sample to degrade. “So, some things have a half-life of 300 years and others have a half-life of 50 years, but between now and 300 years some of that plastic degrades,” he said. “The microplastics we’re seeing in the environment are probably 40 or 50 years old.”

Although microplastics are already in our bodies, it is unclear what, if any, health effects they may have. Traditionally, plastics are considered biologically inert, he said, but some microplastics are so small they are measured in nanometers — a billionth of a meter — and can penetrate cell membranes. Able to cross.

Campion said the increased concentration of microplastics in human tissues could explain the surprising increase in certain types of health problems, such as inflammatory bowel disease and colon cancer in people under 50, as well as sperm. Decline in numbers.

The concentration of microplastics in the placenta is particularly troubling, he said, because the tissue has been growing for only eight months (it starts forming around one month into pregnancy). “Other parts of your body have been accumulating for quite a long time.”

Kempen and his colleagues are planning more research to answer some of these questions, but in the meantime they are deeply concerned about the increasing production of plastic around the world.

“It’s only going to get worse, and the pace is that it’s going to double every 10 to 15 years,” he said. “So, even if we stop it today, there will be three times more plastic in the background in 2050 than there is now. And we’re not going to stop it today.”