Micro and nanoplastics found in human tissues

On August 18, a team of researchers presented to the American Chemical Society (ACS) Fall 2020 Virtual Meeting & Expo the results of a research that analyzed 47 human tissue samples with mass spectrometry and found that “they contained monomers, or plastic components “.

Plastic pollution of soil, water and air is a global problem and animals and humans can ingest the particles produced by the degradation of plastic, with still uncertain health consequences. Now, scientists report that they have examined micro and nanoplastics in human organs and tissues for the first time.

Charles Rolsky, an Arizone State University researcher who presented the study at the ACS meeting, explains that “We find macro, micro and nano plastics in virtually every place in the world and in a few decades we have gone from seeing plastic as a wonderful advantage to consider it a threat. There is 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 if this plastic is just a nuisance or if it represents a danger to human health ».

Microplastics are plastic fragments with a diameter of less than 5 mm, nanoplastics are even smaller, with diameters of less than 0.050 mm. Wild animal research and laboratory animal models have linked exposure to micro and nanoplasty to infertility, inflammation and cancer, but human health outcomes are currently unknown. Previous studies have shown that plastic can pass through the human gastrointestinal tract, but Rolsky and Varun Kelkar, another author of the new research and also from Arizona State University, are investigating whether these tiny particles accumulate in human organs and how to detect them. . To find out, the researchers collaborated with Diego Mastroeni of the ASU-Banner Neurodegenerative Disease Research Center, to obtain samples from a large archive of brain and body tissues used to study neurodegenerative diseases, such as Alzheimer’s. Samples were taken from the lungs, liver, fatty tissue, spleen and kidneys – organs susceptible to being exposed to plastic and microplastic monomers and filtered or collected. To develop a method and test it, the team added nano / microplastic beads to this sample set. Then, they analyzed the sample with flow cytometry and the researchers showed that they could detect the beads they had introduced into the samples. Then they also created a computer program that converts plastic particle count information into units of mass and surface area, and they plan to share this tool online so other researchers can report their results in a standardized way. Halden is convinced that “This shared resource will help build a database on plastic exposure so that exposures in organs and groups of people can be compared over time and geographic space.”

To the ACS they underline that “The flow cytometry method has allowed researchers to demonstrate that they can detect nano / microplastics from the tissues to which they were added. The researchers also demonstrated the effectiveness of using μ-Raman spectrometry to study environmental contamination with microplastics, including polycarbonate (PC), polyethylene terephthalate (PET) and polyethylene (PE). The flow cytometry method allowed the researchers to demonstrate that they could detect nano / microplastics from the tissues to which they were added. The researchers also demonstrated the use of μ-Raman spectrometry to study environmental contamination with microplastics, including polycarbonate (PC), polyethylene terephthalate (PET) and polyethylene (PE) “.

Next, the researchers used mass spectrometry to analyze 47 human liver and adipose tissue samples. No material was added to these samples, but the team still found plastic contamination in the form of monomers, or plastic fragments, in each sample. Bisphenol A (BPA), still used in many food containers despite causing health problems, was found in all 47 human samples.

As far as the researchers know, their study is the first to examine the presence of monomers, nano and microplastics in the human organs of individuals with a known history of environmental exposure. Halden points out that ‘Tissue donors have provided detailed information on their lifestyle, diet and occupational exposures. Because these donors have such well-defined histories, our study provides the first clues about the potential sources and routes of exposure of micro and nanoplastics ».

But should people be concerned about the high frequency with which plastic has been detected in human tissues? Kelkar concludes: “We never want to be alarmist, but it is worrying that these non-biodegradable materials that are present everywhere can penetrate and accumulate in human tissues, and we do not know their possible health effects. Once we have a better idea of what is in the tissues, we can conduct epidemiological studies to evaluate the results on human health. This way, we can begin to understand the potential health risks, if any. ‘