Micro- and nanoplastics detected in human tissues

Plastic pollution of land, water and air is a global problem. Even if plastic bags or water bottles break to the point that they are no longer an eye, small fragments can still contaminate the environment. Animals and humans can absorb the particles, with unclear health consequences. Now scientists report that they are the first to study micro- and nanoplasts in human organs and tissues.

The researchers will present their results today at the American Chemical Society (ACS) Fall 2020 Virtual Meeting & Expo.

“You can find plastic that contaminates the environment at just about any location in the world, and in a few short decades we’ve moved away from seeing plastic as a wonderful advantage to considering it a threat,” he says. Charles Rolsky, who will present the work at the meeting. “There is evidence that plastic is making its way into our bodies, but very few studies have looked into it. And at this point we do not know if this plastic is just a nuisance or if it is a danger to human health. . “

Scientists define microplastics as plastic fragments less than 5 mm, or about 0.2 inches, in diameter. Nanoplasts are even smaller, with diameters less than 0.001 mm. Research in wild and animal models has linked micro- and nanoplastic exposure to infertility, inflammation and cancer, but human health outcomes are currently unknown. Previous studies have shown that plastic can pass through the human digestive tract, but Rolsky and Varun Kelkar, who also presented the research at the meeting, questioned whether the small particles accumulate in human organs. Rolsky and Kelkar graduated from 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 set up to study neurodegenerative diseases, such as Alzheimer’s. The 47 samples were taken from lungs, liver, spleen and kidneys – four organs likely to be exposed to, filtered or collected microplastics. The team developed a procedure to extract plastic from the samples and analyze them by μ-Raman spectrometry. The researchers also created a computer program that converts information about plastic particle count into units of mass and surface area. They plan to share the tool online so other researchers can report their results in a standardized way. “This shared resource will help build a database of plastic exhibits so we can compare exhibits in bodies and groups of people over time and geographic space,” says Halden.

The method allows researchers to detect dozens of types of plastic components within human tissues, including polycarbonate (PC), polyethylene terephthalate (PET) and polyethylene (PE). As paired with a previously developed mass spectrometry assay, plastic contamination was detected in each sample. Bisphenol A (BPA), still used in many food containers despite health concerns, was found in all 47 human samples.

To the knowledge of the researchers, their study is the first to examine micro- and nanoplastic performance in human organs from individuals with a known history of exposure to environment. “The tissue donors provided detailed information about their exposures to lifestyle, diet and occupation,” says Halden. “Because these donors have such well-defined histories, our study provides the first indications of potential sources and routes of micro- and nanoplastic exposure.”

Should people be concerned about the high detection frequency of plastic components in human tissues? “We never want to be alarmist, but the point is that these non-biologically degradable materials that are ubiquitous can enter and retrieve in human tissues, and we do not know the potential health effects,” says Kelkar. “Once we get a better idea of ​​what’s in the tissues, we can conduct epidemiological studies to assess the outcomes of human health. In this way, we can begin when we understand the potential health risks.”