Scientists Can Detect Microplastics in Human Tissues

For the first time, plastic fragments have been shown to accumulate in the human body.

plastic bottle on a plate
Plastic waste like this bottle break down into tiny particles that can enter the human body.

@sashapritchard via Twenty20

Scientists have detected micro- and nano-plastic particles in human tissues and organs for the first time. While it is known that plastic particles have contaminated every corner of the planet and infiltrated countless animal species, relatively little is known about their presence in the human body, beyond the fact that they can pass through the gastrointestinal tract. But now researchers have found that plastic particles can, in fact, accumulate in brain and body tissues. These are extremely tiny: Microplastics measure less than 5 millimeters, or 0.2 inches, in length, while nanoplastics have diameters less than 0.001 millimeters.

Using 47 samples taken from lungs, liver, spleen and kidneys – all organs that are likely to be exposed to microplastics due to their filtering capacities – the researchers from Arizona State University spiked them with dozens of types of micro- and nano-plastics in order to see if they could detect the various plastics using a method called flow cytometry. They were able to tell exactly what was there, including polycarbonate (used to make refillable water bottles and jugs), polyethylene terephthalate (used in polyester fabrics and disposable plastic food and beverage containers) and polyethylene (used to make plastic bags and films). This part of the experiment demonstrated that flow cytometry can be used for this kind of analysis.

In a second experiment, the researchers did not spike the tissues with plastic, but used mass spectrometry to analyze the tissues. They detected plastic contamination in the form of monomers. Monomers are the small molecules that react together to make plastics – the "building blocks" of plastics. Bisphenol A (BPA) was also found in every sample.

This is concerning because it shows what is possible, and microplastics are not something humans should have in their bodies. Microplastics are known to cause inflammation, infertility, and cancer in animals, but little is understood yet about their effect on human health. BPA is a notorious reproductive toxicant that disrupts hormonal and sexual development. It has been removed from many products in recent years, but its common replacement, Bisphenol S (BPS), is considered to be just as harmful.

Varun Kelkar, an ASU graduate student who was part of the research team, said in a press release:

"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. 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."

The 47 samples were taken from donors who also provided detailed information about their lifestyles, diets, and occupational exposures; this will help the researchers to narrow down potential sources of exposure regarding the monomers that were detected.

The researchers also created an online tool that converts a plastic particle count into units of mass and surface area. It will be made publicly available, in hopes of building a "plastic exposure database" that will allow researchers to "compare exposures in organs and groups of people over time and geographic space."

While these findings are not yet part of a peer-reviewed study, they are being presented this week at a meeting of the American Chemistry Society. It's yet another powerful reminder of just how important it is to fight plastic pollution – and to tackle the root of the problem, which is the consumption of so many products that use plastic.

Note: This article was updated on August 20, 2020, to reflect changes that were made by the American Chemical Society on August 18, clarifying its press release.