We use so much plastic that we are now surrounded by plastic. But eventually all plastic degrades into tiny pieces called microplastics and nanoplastics. These tiny plastic pieces are found throughout the world, including in the food we eat and water we drink, especially bottled water. A few years ago researchers even found microplastics in the feces of people - meaning they ingested microplastics, which traveled through the intestines, and then eventually excreted.
But the big question remained: Do some microplastics get absorbed into human tissues?
Two Arizona State University researchers looked into this and found small parts of plastics (plastic monomers) in the tissues of every single person examined. They analyzed 47 human tissue samples (using mass spectrometry) taken from deceased persons who had donated their bodies to science. All had plastic particles in the lungs and adipose (fat) tissue. For example, they found BPA (bisphenol A - an endocrine disruptor) in every single sample. Other examples of plastic particles found were polypropylene and polysterene.
Currently it is unknown if there are health consequences from plastic particles being absorbed into our tissues. However, wildlife and animal research has linked microplastic and nanoplastic exposure to infertility, inflammation, and cancer. Once plastic is absorbed by tissues, it will stay there - it will not biodegrade. Whether there are human health effects is a very important issue because more and more plastic is produced each year, which means exposure to more plastic particles over time, and accumulation in our bodies.
Note that microplastics are plastic fragments less than 5 millimeters in diameter (many can be seen by the human eye), while nanoplastics are even smaller with diameters of less than 0.050 millimeters (these can not be seen by the human eye).
Excerpts from an American Chemical Society press release about research presented to the American Chemical Society in August 2020: Micro- and nanoplastics detectable in human tissues
WASHINGTON, Aug. 17, 2020 — Plastic pollution of land, water and air is a global problem. Even when plastic bags or water bottles break down to the point at which they are no longer an eyesore, tiny fragments can still contaminate the environment. Animals and humans can ingest the particles, with uncertain health consequences. Now, scientists report that they are among the first to examine micro- and nanoplastics in human organs and tissues.
“You can find plastics contaminating the environment at virtually every location on the globe, and in a few short decades, we’ve gone from seeing plastic as a wonderful benefit to considering it a threat,” says Charles Rolsky, Ph.D., who is presenting the work at the meeting. “There’s evidence that plastic is making its way into our bodies, but very few studies have looked for it there. And at this point, we don’t know whether this plastic is just a nuisance or whether it represents a human health hazard.”
Scientists define microplastics as plastic fragments less than 5 mm, or about 0.2 inches, in diameter. Nanoplastics are even smaller, with diameters less than 0.050 mm. Research in wildlife and animal models has linked micro- and nanoplastic exposure to infertility, inflammation and cancer, but health outcomes in people are currently unknown. Previous studies have shown that plastics can pass through the human gastrointestinal tract, but Rolsky and Varun Kelkar, who is also presenting the research at the meeting, are studying if the tiny particles accumulate in human organs and how to detect them. Rolsky is a postdoctoral scholar and Kelkar is a graduate student in the lab of Rolf Halden, Ph.D., at Arizona State University.
To find out, the researchers collaborated with Diego Mastroeni, Ph.D., to obtain samples from a large repository of brain and body tissues that was established to study neurodegenerative diseases, such as Alzheimer’s. Samples were taken from lungs, liver, adipose tissue, spleen and kidneys –– organs likely to be exposed to, filter or collect plastic monomers and microplastics.
Next, the researchers used another method called mass spectrometry to analyze 47 human liver and fat tissue samples. No materials were spiked into these samples. The team found plastic contamination in the form of monomers, or plastic building blocks, in every sample. Bisphenol A (BPA), still used in many food containers despite health concerns, was found in all 47 human samples.
Should people be concerned about the high detection frequency of plastic components in human tissues? “We never want to be alarmist, but it is concerning that these non-biodegradable materials that are present everywhere can enter and accumulate in human tissues, and we don’t know the possible health effects,” Kelkar says. “Once we get a better idea of what’s in the tissues, we can conduct epidemiological studies to assess human health outcomes. That way, we can start to understand the potential health risks, if any.”
[NOTE: A press conference on this topic was held Monday, Aug. 17, at 12 p.m. Eastern time online at http://www.acs.org/fall2020pressconferences. Scroll through the topics to topic Micro- and nanoplastics detectable in human tissues. Very interesting!]