Microscopic specks of plastic can be found in practically every nook and cranny of Earth’s environment. For the first time, scientists have now shown that microplastics and nanoplastics can be found in the organs and tissues of humans.

Scientists at Arizona State University discovered the presence of at least one form of plastic in all 47 samples taken from the lungs, liver, spleen, and kidneys of deceased people who had donated their body to science. 

Bisphenol A (BPA), a precursor to important plastics used for food containers and packaging, was found in 100 percent of the samples studied. The team also found types of plastic commonly used in consumer products, such as polycarbonate (PC), polyethylene terephthalate (PET), and polyethylene (PE) in many of the samples.

The researchers presented their findings on Monday, August 17, at the American Chemical Society (ACS) Fall 2020 Virtual Meeting & Expo, in which they explained that μ-Raman spectrometry imaging techniques were used to reach these conclusions. 

“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,” Charles Rolsky, a researcher of aquatic microplastics at Arizona State who is presenting the work at the meeting, said in a statement. “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."

Microplastics are defined as plastic fragments less than 5 millimeters in diameter, while nanoplastics are even smaller with diameters of less than 0.001 millimeters. 

Back in 2018, scientists revealed that human poop is riddled with microplastics, indicating the materials are pervasive in the human gut. The researchers also suggested it was fairly inevitable that the smallest microplastic particles were capable of entering the bloodstream, lymphatic system, and perhaps liver. However, this new research is the first time scientists have directly examined microplastics and nanoplastics in human organs and tissues.

All of the donors had provided the researchers with a detailed history of their lifestyle, diets, and jobs, so the team says they managed to gain some insight into how these human-made materials became deeply integrated into their bodies.   

The idea of non-biodegradable industrial materials lurking in your liver might sound pretty grim, but the researchers were quick to point out that the health implications of this are not yet clear. 

“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.”

Broadly speaking, the effects of microplastic on animal health are not widely agreed upon. The World Health Organization (WHO) has said there’s “no evidence to indicate human health concern” of microplastics in drinking water, although they added this is based on the limited amount of information currently available. 

On the other hand, some research has suggested otherwise. Many of these concerns focus on Bisphenol A (BPA). The US Food and Drug Administration (FDA) says that BPA is considered safe at the current levels occurring in foods, although they note there is some concern about the potential effects of BPA on the brain, behavior, and prostate gland in fetuses, infants, and young children. 

Regardless of its effect on health, the discovery of microplastics and nanoplastics in human organs certainly goes to show how pervasive these human-made materials have become in under a century.

Edited 19/08/2020: This article previously suggested that Bisphenol A (BPA) was a type of plastic when it is actually a compound used in the manufacturing of certain plastics. The article has since been corrected.